Until the internal anatomy of 'wet' specimens has been fully described, the status of many of the genera listed here is uncertain.

These are sand dwellers or they live on muddy bottoms, in bays, estuaries, and close to the shore in tidepools.

The shell is partially or completely enfolded by lateral parapodial (=fleshy winglike outgrowths) lobes.

The thin outer lip of the aperture extends beyond the apex of the shell and is thus longer than the body whorl.

Their eggs are deposited in round or oval jellylike strings, attached to eelgrass or sand.