Wentletraps are small, often white, very high-spired, predatory or ectoparasitic sea snails, marine gastropod mollusks in the family Epitoniidae.

The word wentletrap originated in Dutch (wenteltrap), and it means spiral staircase. These snails are sometimes also called "staircase shells", and "ladder shells".

The family Epitoniidae belongs to the superfamily Epitonioidea. Since 2017 this family also includes the former families Janthinidae (the pelagic purple snails) and Nystiellidae, all part of the informal group Ptenoglossa.

Epitoniidae is a rather large family, with an estimated number of species about 630.

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