Cystiscinae are a taxonomic subfamily of minute sea snails.

These are marine gastropod mollusks or micromollusks in the family Cystiscidae, and the clade Neogastropoda.

Shell minute to small, white; spire immersed to low; surface smooth or axially costate; lip thickened, smooth or denticulate; external varix absent; siphonal notch absent; posterior notch absent; columella multiplicate, with combined total of usually 2 to 8 plications plus parietal lirae; internal whorls cystiscid type.

Animal mantle smooth, at least partially extending over external shell surface.

Internal anatomy unknown.