Description, Shell up to 8.50 mm wide, markedly broader than high, strongly depressed, thin, umbilicate, nacreous white. Protoconch of 1 smooth, convex whorl.
Teleoconch of up to 5 regularly expanding whorls; spire outline flat, shallowly concave, or shallowly convex; spire whorls flat or very shallowly convex; periphery sharply or very sharply angulate; base shallowly convex. Shoulder angulation always weak, retained throughout or confined to earliest whorls. Sculpture absent or consisting of a few basal spiral threads and beading or undulations on the periphery, or fine, crisp, reticulating spiral threads and collabral axial riblets. Umbilicus deep, wide. Aperture subrhomboidal. Outer lip thin, simple within; posterior notch shallow, its depth 6-11% of shell diameter; basal notch smaller; no peripheral notch. Inner lip thin, simple. Operculum: horny, transparent, circular, spiral, tightly coiled, of about 12 whorls; nucleus almost central.
Radula with the formula c. 6 + 1 + 1 + 1 + c. 6. Central tooth rather short, subquadrate, not waisted near base; cutting area broadly angular, finely and sharply serrate. Lateral teeth broadest, broader than long, subtriangular, inequilateral; cutting area narrowly angular, sharply and narrowly serrate. Marginal teeth long, narrow, narrowing outwards, strongly curved; cutting area with sides sharply and narrowly serrate; distal cusp long, smooth.
Fluxinella species are characterised by the combination of strongly depressed spire, weak shoulder angulation, sharply angulate periphery, wide umbilicus, very shallow posterior notch, simple inner lip, smooth protoconch, and multispiral operculum. The radula is typically conservative, but is distinctive as regards the rather short, broad cutting area on the central tooth. Apart from the species described below, the genus includes Fluxina discula Dall (1889), F. solarium Barnard (1963), and Fluxiella vitrea Okutani (1968). Fluxina brunnea Dall, 1881 has superficially similar shell facies, but is now placed in the trochid subfamily Calliostomatinae, as an earlier name for Calliostoma (Astele) tejedori Aguayo, 1949 (Merrill 1970).