Shell equivalve, inequilateral with umbones at the anterior 1/3 of length. Outline almost rectangular, longer than high, often irregular with a distinct keel at the posterior end. Ligament posterior to beaks. Coarse sculpture, consisting of lamellae crossed by radial riblets more prominent posteriorly. Taxodont hinge; central teeth smaller, marginal teeth larger. Adductor muscle scars slightly raised. Inner margin crenulate. Ventral margin with a narrow byssal sinus.
white to dirty white, tinged with orange or pink.
common size :
shell to 30 mm.
The small size and the decussate sculpture dominated by concentric lamellae which are somewhat raised at the posterior part and the prominent muscle scars are diagnostic for the species.
BIOLOGY / ECOLOGY
Epifaunal, sedentary, bysally attached organisms. Suspension feeders.
attached to corals and rocks. The Mediterranean specimen under stone on the shore.