The shell is inflated and brittle and the right valve is slightly larger and more convex than the left one.

The surface is sculptured with fine concentric lines and a slight ridge extends from the umbone to the margin of the valve on the posterior end.

On the inside of the valve, the posterior adductor muscle scar is large and triangular while the anterior one is long and thin.

[2] Thracia convexa is found in the north east Atlantic, its range extending from Norway to the Mediterranean Sea.

It is distributed widely round the coasts of Britain where it burrows in sandy or muddy substrates, extending its siphons to the surface to breathe and feed.