The median groove is a distinctive feature, noticed by the british paleontologist S. V. Wood, who wrote in 1839: « The central costae are angulated, dwingling into striae on the sides, visible internally, crenulating the margin in front. » – “Descriptions of the species of the genus Lima, from the Coraline Crag etc.” in Annals and Magazine of Natural History, vol. III, London 1839.

Leach, about his Lima unicostata: « Shells pellucid, with vertically elevated lines; one of the middle lines is elevated and forms a rib; both valves immediately under the rib are channeled; the epidermis white. Pecten subauriculatus, Mont. Test. Brit. Supp. 63; Flem. Edinb. Encycl. vii. 98. Ostrea subauriculata, Turt. Conch. Dict. 131. This species occurs, but very rarely, in deep water in sandy bottoms. » – W. E. Leach: Molluscorum Britanniae Synopsis, London 1852, p.348.