Description
This snail can be found in large numbers in the tidal zone, on or underneath stones. It has a strong shell, with several whorls. The shell can be closed with an operculum. The shell is typically grooved, which can be less obvious with older specimens because of wear. They feed on algae that they graze of rocks and stones. After fertilization the eggs with a diameter of 1 mm are released into the water. After 1 week the eggs will hatch. The larvae are planktonic the first few weeks. After they reached the seafloor, the journey to the shore starts.

Size
About 35 mm tall.

Colour
Dark green to greyish brown, can be bleached by the sun.

Habitat
In the tidal zone.

Distribution
North Atlantic, in Europe from the White sea till north Spain.