Nystiellidae is a family of small sea snails, marine gastropod mollusks within the superfamily Epitonioidea which includes the wentletraps, the purple snails and their allies.
Murdochella is a genus of small sea snails, marine gastropods in the family Nystiellidae of the superfamily Epitonioidea, the wentletraps, the purple snails, and their allies.