Shell almost equivalve with lv slightly flatter. Outline subovate - subtruncate. Inequilateral, umbo at the posterior 1/3 of the valve. Anterior margin rounded; posterior margin narrow, subtruncate, flexous. Sculpture of concentric lines and very faint radial striations most visible on rv. Ligament external but obsolete. Hinge with 2 cardinal teeth in each valve, left posterior becoming obsolete. No lateral teeth. Pallial sinus extending to the middle of the shell.
white rather porcellanous, periostracum straw colored.
common size :
to 50 mm in length.
Externally resembles Abra from which it differs in having more solid shell, different ornamentation of shell and distinctly different dentation.
BIOLOGY / ECOLOGY
Infaunal siphonate, unattached animals: the genus comprises surface deposit feeders, burrowing actively into the sediment in muddy and sandy substrata.
muddy sands in shallow water; dredged from 120-180 m muddy substrata.