Splendrillia nenia is a species of sea snail, a marine gastropod mollusk in the family Drilliidae. The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the Mollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to quite large. There are huge numbers of sea snails and sea slugs, as well as freshwater snails and freshwater limpets, and land snails and land slugs.