Shell elongate, often strongly inequilateral (umbones subcentral or very close to the anterior extremity). Valves gaping at both ends.
 

« Shell elongated, linear, slightly curved, more or less truncated and gaping at both ends. Hinge: in the left valve a perpendicular lamellar cardinal tooth; a hymenal lamellar tooth, horizontal, exposed at the anterior end. In the right valve two cardinal teeth almost conoid, slightly lamellar, perpendicular, with an intermediate slit; the horizontal hymenal tooth is smaller than that of the other valve. In each valve the cardinal edge is thick, convex, smooth over almost its entire length. » – C. F. Schumacher: Essai d’un nouveau système des habitations des vers testacés, Copenghagen 1817, p.143.
 

Synonym Ceratisolen Forbes, who writes: « Shell greatly elongated transversely, compressed, equivalve more or less inequilateral, thin, gaping at the extremities. Surface diagonally comparted, centrally radiato-striate, invested with an epidermis. Muscular impressions distinctly marked, dissimilar, resembling those of Solen; pallial impression with a wide short sinus. Hinge subcentral, complicated, […] Ligament external. Valves beneath the hinge strengthened by a strong oblique rib. » – Forbes & Hanley: British Mollusca vol.I, London 1853, p.255.
 

Shell small, with the umbones subterminal, an almost straight dorsal margin; left valve with two cardinals (the posterior one markedly bifid) and 1 posterior lateral; right valve with 1 cardinal and 1 posterior lateral.