Anodontia (Euanodontia) ovum (Reeve, 1850) (Figs 2C, D; 3B) Lucina ovum Reeve, 1850: pl. 5, species 21. Anodontia (Euanodontia) ovum – Taylor & Glover 2005: 310, figs 28, 31AB. TYPE MATERIAL. — 2 syntypes (BMNH 1963195 /1-2). TYPE LOCALITY. — Isle of Burias, Philippines. MATERIAL EXAMINED. — Koumac. 5 stn, 0-2 m, 14 v. Touho. 8 stn, 0-8 m, 13 live, 384 v. Lifou. 2 stn, 0-16 m, 2 v. Other New Caledonia. LAGON, Nouméa, Ouen Toro, 22°17’S, 166°27’E, intertidal, 2 v. — Secteur de Bourail, chenal du lagon de Poe, stn 1326, 21°37’S, 165°22’E, 1-3 m, 3 v. DISTRIBUTION. — This species is widely distributed across the IWP from the Red Sea to Society Islands and north to Okinawa, often on oceanic islands and reefs (Taylor & Glover 2005). It inhabits intertidal and shallow subtidal sands, usually associated with seagrass beds. DESCRIPTION Medium sized, H to 35 mm, L to 39 mm, moderately inflated T/L 0.29, circular in outline H/L 0.92. Colour white. Shell surface with low commarginal growth increments and halts. Umbones small. Lunule short, lanceolate, slightly impressed, slightly asymmetrical, larger in right valve. Hinge short, thin, curved, edentulous. Ligament internal, deeply inset in short nymph. Anterior adductor scar detached from pallial line for about 70% of length at an angle of about 30°. Interior of shell often glossy, sometimes pale yellow inside pallial line and spotted with small, round, translucent scars and occasional radial striations. Pallial line entire, relatively close to shell edge. REMARKS Anodontia ovum is similar in size and shape to Anodontia vesicula (Gould, 1850) but the latter species has a pallial line divided into discrete blocks (Figs 2F; 3D), a less inflated shell and a larger lunule. In the Pacific, Anodontia ovum overlaps in range with Anodontia hawaiensis and could be confused, but the latter species is smaller, has a truncate posterior margin and is more attenuated anteriorly.

Published as part of Glover, Emily A. & Taylor, John D., 2007, Diversity of chemosymbiotic bivalves on coral reefs: Lucinidae (Mollusca, Bivalvia) of New Caledonia and Lifou, pp. 109-181 in Zoosystema 29 (1) on page 114, DOI: 10.5281/zenodo.5392295