Cucullaea labiata is a species of saltwater clam or ark shell, a marine bivalve mollusk in the family Cucullaeidae.

The left valve is a little larger than the right and the shape is roughly triangular with a long, rounded margin.

The rest of the valve has further fine ribs but also concentric sculpturing giving it a reticulated pattern.

The exterior of the shell is purplish-brown and the inside white, shaded with reddish-brown posteriorly.

Right and left valve of the same specimen: Cucullea labiata is found in the Indo-Pacific, from northern India to Japan and New South Wales in Australia.