A family that contains the genus Mnestia (Ventomnestia is now considered a synomyn). The family was raised in 2015 due to uncertainty of phylogenic relationships (formerly in Haminoeidae).
This family is considered distinct through DNA sequencing and the following features: Although possessing ridged gizzard plates the presence of a radula excludes it from Retusidae and the radula formula does not match Haminoeidae. The shell is small, thick, cylindrical and with coloured bands and spiral striations. Genera with a similar shell shape have white shells.
The following features are common with other families: Distinct spiral striae are present throughout the shell and the inner whorls are absorbed. The shell is truncated posteriorly.
The body can generally withdraw completely into the shell. The head shield is broad with the posterior edge usually developed into a pair of lobes and with discernible eye spots located dorsally, close to the surface.
There is a broad foot though it is shorter than the shell. The gill is not visible externally.