|Original name||Amussium jeffreysii Smith, 1885|
|Autoreference||Smith, 1885: 310, pl. 23, figs 2-2c.|
|Reference||Smith, E.A., 1885. Report on the Lamellibranchiata collected by H.M.S. "Challenger" during the years 1873-1876. - Challenger Reports, Zoology, 13 (35): 1-341.|
|Type data||Lectotype (pr: H 20.3 mm, L 18.6 mm, D 4.9 mm) The Natural History Museum, London (BMNH 1818.104.22.16813), designated by Dijkstra (2001: 76). Type locality: Philippine Islands, 09*26'N, 123*45'E, 686 m, alive, blue mud, 25.01.1875 ("Challenger" stn 210).|
Shell up to ca. 25 mm high, fragile, semi-transparent, weakly inflated, left valve slightly more convex than right valve, subcircular, inequivalve, nearly equilateral, auricles of left valve nearly equal in size and shape, of right valve unequal, colour of left valve creamy or orange-tinted, right valve whitish.
Left valve with numerous, irregularly spaced, weak and delicate antimarginal lirae and very weak, regularly spaced, commarginal lirae. Commarginal lamellae near ventral margin. Auricles nearly smooth or very finely sculptured with concentric lamellae.
Right valve with commarginal sculpture. Marginal apron often broken off. Internal ribs 9-12 (usually 12) with 2 auricular riblets and some interstitial rudimentary riblets near the margin. Byssal notch very small, byssal fasciole and ctenolium lacking.
Gulf of Aden, Laccadive Sea, Japan, East and South China Sea, Philippines (TL), Indonesia, Coral Sea, Loyalty Islands, Wallis and Futuna Islands, Vanuatu Archipelago
|Habitat||Living bathyally on soft bottom assemblages.|