No useful definition, but the arrangement of the teeth seems to be shared by at least two genera…
 

« Shell minute, equivalve, slightly inflated, subcircular to suboval, slightly inequilateral with beaks anterior to the vertical midline, slightly prominent, prosogyrous. Protoconch almost circular, with a smooth or granulated surface, surrounded by a clearly demarcated smooth rim along its margin. Teleoconch with concentric ridges, sometimes also with radial sculpture or microsculpture. Periostracum thin, inconspicuous. » Hinge: left valve with two anterior cardinals fused proximally and one elongate posterior lateral; right valve with three divergent cardinals and two posterior laterals; the hinge extends along almost the whole dorsal margin. « A well developed internal ligament, below the beaks and directed obliquely backwards, occupying a small part of the available space between cardinals and posterior laterals. A very small external ligament, between the beaks, extending slightly onto the dorsal margin. Interior margin of the shell smooth. Two suboval adductor muscle scars, impressed beneath the anterior and posterior ends of the hinge plate. Pallial line entire [no pallial sinus] or weakly deflected posteriorly, generally well defined. » – Salas & Gofas: “ Description of four new species of Neolepton Monterosato, 1875 (Mollusca: Bivalvia: Neoleptonidae), with comments on the genus and on its affinity with the Veneracea”, Ophelia 48(1), pp.37-39.