Diagnosis
Shell solid, ovate-trigonal, moderately inflated, solid, glossy; umbones strongly prosogyrate; lunule heart-shaped to lanceolate, raised, well delineated by incised line; shell with a weakly defined fold extending from umbones to the posteroventral margin. Sculpture of fine growth striae dominated by crowded, raised concentric ridges developed as rounded ribs, which become slightly wrinkled or disjunct at the anterior and posterior extremities; rib interstices narrow, shallow. Colour externally cream-white with sparse, obscure, irregularly spaced lines and small triangles; umbones and lunulc white; shell internally white. Shell length to 18.5 mm.

Distribution and habitat
Known only from New Caledonia, in coarse sand to 42 m. Holotype. New Caledonia: Secteur des Belep: stn 1103, 19°43'S, 163°57'E (lpv) 32 m, MNHN.
Paratypes. New Caledonia: Secteur des Belep: same data as holotype (2pv, 2 rv, llv); stn 1129, 19°29'S, 163°49'E (7pv); stn 1117, 19°38'S, 163°54'E (5pv) 40 m; stn 1168 (llv); Lagon Nord: stn 484, 19°00'S, 163°35'E (lpv) 35 m; stn 517, 19°09'S, 163°35'E (2pv) 42 m; stn 522, 19°08S, 163°38'E (4pv) 42 m, MNHN; stn 1129, 19°29'S, 163°49'E, 40 m, AMS C.312630 (lpv).

This species is most similar to Lioconcha. melharteae, especially in relation to size (maximum 20 mm) and the structure of the close-set concentric ridges (see also Remarks for L. melharteae). However, L. caledonensis differs in having valves that are markedly thicker, less inflated and more angulate in shape than those of L. melharteae. Moreover, the brown-flecked, poorly developed colour pattern of L. caledonensis contrasts with the predominantly white shell of L. melharteae, which is coloured by a single, large orange ray posteriorly and an orange dorsal margin and lunule. Other heavily ridged Lioconcha species (L. philippinarum, L. richerdeforgesi, L. trimaculata and L. gordoni) differ substantially in colour pattern, size and valve shape from L. caledonensis and are unlikely to generate any confusion.