Shell is fragile, slightly inequivalve, right valve a little more convex than the left. Inequilateral, beaks in the posterior half, directed inwards and backwards. Regularly oval in outline with a slight twist to the right near the posterior border in both valves. Ligament is a prominent light brown arched band deeply inset, reaching nearly half-way to the posterior margin. Sculpture of evenly spaced concentric ridges. Growth stages are clear. Right valve with two small cardinal teeth, of which posterior is bifid, and single anterior and posterior laterals, both prominent. Left valve with two cardinal teeth, of which the anterior is bifid, and one anterior and one posterior lateral tooth, both weak. The base of the anterior lateral tooth of the right valve extends to the base of the posterior cardinal. Anterior adductor scar slightly larger than the posterior. Pallial sinus a deep incision, its lower border confluent with the pallial line. Margin is smooth (T. pygmaea-drawing).
Up to 9.5 mm in length.
Colour very variable, white, pink, orange, or red-brown, sometimes with streaks or blotches and occasionally with a radiating streak running from the beaks. Periostracum is rarely retained. Interior of shell variable in colour, generally being the same shade as the exterior.
A deep burrower in sand or mud. This habit has had effect in developing a powerful foot and in lengthening and separating the siphons. The lips are large, the gills are unequal in size and the mantle is fringed with tentacles (Tellina sp.-animal).
Inhabits coarse sand and shell-gravel from just offshore, to about 145 metres.
It is distributed from northern Norway (about 70°N), to the Iberian Peninsula, into the Mediterranean (Distr. T. pygmaea) and along the Atlantic coast of Morocco, to the Cape Verde Isles, French Guinea and the Ivory Coast.