Wikipedia
Persiculinae
Persiculinae is a taxonomic subfamily of minute to small predatory sea snails, marine gastropod mollusks. This subfamily includes several species which are micromollusks.
The subfamily is sometimes placed in the family Cystiscidae, and is sometimes instead left in the family Marginellidae the margin snails. It is within the clade Neogastropoda.
(Note: Gastropod taxonomy has been in flux for more than half a century, and this is especially true currently, because of new research in molecular phylogeny. Because of all the on-going changes, different reliable sources can yield very different classifications.)