Shell equivalve, inequilateral, heart-shaped in side view, with prominent umbones; almost always a strong radial sculpture. Two cardinals in each valve; laterals elongate, laminar. No pallial sinus.
 

Shell medium-sized to large, heavy, often thick, inequilateral; valves slightly gaping posteriorly, or not gaping; sculpture of strong radial ribs, triangular, more or less spatulate, spiny or simply squamose, depending of the species; interspaces and radials crossed by minute concentric ribs. Inside: the outer radials are apparent; adductor muscle scars hardly visible. Hinge: on the right valve, two small sharp cardinals close together, two anterior laterals diverging, one posterior lateral; on the left valve, two small sharp cardinals close together, a strong anterior lateral and a weak posterior lateral; ligament external.
 

shell small, « with the posterior area distinctly demarcated by an angulate radial ridge; and a rib sculpture of commarginal nodes or scales. » – Wells, Ross & Beesley: Mollusca: The Southern Synthesis part A, Melbourne 1998, p.331. The genus is close to Parvicardium Monterosato.
 

Shell small to medium-sized, subtriangular, transverse; sculpture of rounded or flattened radial ribs crossed by obsolete commarginal striae or plicae; hinge: strong lamellar laterals; ventral margin intensely crenated inside.
 

Shell small to large, often thin, subcircular, slightly inequilateral, convex, rarely gaping posteriorly; sculpture made up of smooth radial ribs. « Hinge plate narrow, thin, moderately curved […]. Cardinals generally unequal and separated in the left valve, approximately equal and touching at their base in the right valve. Posterior lateral in the left valve very low, elongated […]; in the right valve this tooth is higher and triangular. The main anterior lateral in the right valve is thin, pointed and triangular […]. In the left valve the anterior lateral is roughly triangular and is prolonged by a raised narrow ridge, more or less elevated, separated from the dorsal margin by a deep elongated cleft which reaches the cardinal area. » – J. Vidal: “A review of the genus Fulvia Gray”, Apex vol.9, Brussels 1994, p.96-97.
 

Shell medium-sized, oval more or less elongate, inequilateral, with obsolete radials that become stronger near the margins. Valves not gaping. Lateral teeth conspicuous.
 

« Shell fairly small, roundish, somewhat inclined, with weak, rounded edge and several tuberculate rib-like folds, the intervening spaces of which are regularly transversely striated. » – J. Thiele: Handbook of systematic malacology, Bieler & Mikkelsen transl., Washington 1992, p.1338. According to Sacco, this genus is not easy to separate from Parvicardium Monts.
 

Name proposed as a subgenus for the small, oblique and papillose species of the genus Cardium. The differences with Papillicardium are not exactly obvious.
 

« Shell large, slightly longer than high, relatively thin and posteriorly gaping. 14–24 radial ribs, sculptured with horseshoe-shaped scales anteriorly and projecting spines posteriorly. Interspaces wider than ribs, often with a secondary riblet. Anterior cardinal blade-like and posterior cardinal very small in left valve. Cardinal teeth erect, fully separated and similar in height in right valve. » – ter Poorten & La Perna: “The West African enigma: Systematics, evolution, and palaeobiogeography of cardiid bivalve Procardium”, Acta Palaeontologica Polonica vol. 62(4), Warszawa 2017, p. 731. Umbo more or less prosogyrate.