(Müller, 1776)
Description:
A small, solid shell with well developed concentric ridges crossed by radial ribs. The reticulate sculpture is especially distinct on the posterior part of the shell. The umbos are close to each other and the cardinal area is small.
Size:
Up to 1.6 cm.
Colour:
Red-brown. The shell is sometimes covered with a yellow periostracum.
Habitat:
Lives fixed with its byssus to hard substrates. From low tide level down to 4000 m.
Distribution:
All West European coasts. Further reported from the Mediterranean and northern Spain south to Angola (Distr. A. nodulosa).