Fluxinella membranacea is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.
The size of the shell varies between 2.5 mm and 3.4 mm. Its shell has "a smooth spire, flattened summit, persistent shoulder angulation, and distinctly overhung umbilical wall."
This marine species occurs off the Philippines and New Caledonia.