Original taxon: Lucina fragilis.
« Shell thick, oval-circular, inflated; anterior side somewhat shorter, umbones curved and slightly hooked. Lunule small, but the shell before it is sinuous, then becomes prominent and subangulate. […] Color of a hyaline white, sometimes reddish near the umbones. […] Inner margins tinged with yellow. » – R. A. Philippi: Enumeratio molluscorum Siciliae…, Berlin 1836-1844. The ligament is almost internal.
Grau de la Vieille Nouvelle, Port-la-Nouvelle, Aude, Occitania, S. France. 15,5mm. Original pictures provided by A. Bertrand (FR) – (CC BY-NC-SA).
« The nomenclature of this species has had great difficulty in becoming clear and fixed; it is a very regularly rounded shell, very deep, adorned with fine, unequal streaks of growth; hinge transverse, reduced to a furrow below the hooks. » – Ibid.
Valves medium-sized, « very convex, suborbicular although inequilateral; anterior side raised upwards and very diminished, almost as wide as the posterior side, which is more dilated and subtruncated on the anal edge; pallial margin regularly arcuate; hooks swollen, prosogyrate, located near the middle […] Lunule large, deep, well demarcated; dorsal surface domed, strongly depressed in the anal area corresponding to the truncature of the edge; thin growth striae crossed by some very obsolete rays.&nbp;» – Cossmann & Peyot: “Conchologie néogénique de l’Aquitaine - suite (1)”, Actes de la Société linnéenne de Bordeaux vol. 65, Bordeaux 1911, p.254.
A specimen from Dardanelles Strait: beach drift, Kepez, Çanakkale, SW. Marmara Region, NW. Turkey. 13mm.