« Shell trapezoidal, strongly inequilateral, equivalve, with prosogyrous beaks near anterior end. Ventral margin not gaping, smooth. Ligament external, opisthodetic, parivincular. Hinge with two lamellar cardinals and two laterals. Outer surface ornamented with commarginal and radial sculpture. Dimyarian, with subequal adductor muscles. Foot small, grooved, often byssate. Pallial line simple, without sinus. » – Matsukuma & Habe: “Systematic revision of living species of Meiocardia, Glossidae and Glossocardia, Trapezidae (Bivalvia)”, Mémoires du Muséum national d’histoire naturelle vol.CLXVII, Paris 1995, p.91. « The Trapezidae is a very small family of bivalves with only a dozen recognised species assigned to five genera (Huber, 2010). The shells are generally whitish, elongately modioliform or subquadrate in shape, with anteriorly situated umbones. Members are usually found nestling in crevices or holes, singly or in small groups. » – Tan & Low: “Singapore Mollusca 2”, Nature in Singapore 2013 6, p.247.
 

« Shell ovate, elongated, finely radiated from top to base, cylindrical, equivalve, very inequilateral; the summits, weakly marked, are very anteriorly placed; hinge subsimilar; two small cardinal teeth, one of which is subbifid, in front of a sort of lamellar tooth, under a rather weak external ligament; two muscular impressions, small, rounded, distant, united by an abdominal impression, narrow and fairly excavated bakcwards. » – H. M. D. de Blainville: “Mollusques, Mollusca”, Dictionnaire des Sciences Naturelles vol.XXXII, Strasbourg & Paris 1824, p.343.