Nassarius arcularius, common name : the casket nassa, is a species of sea snail, a marine gastropod mollusk in the family Nassariidae, the Nassa mud snails or dog whelks.There are two subspecies : Nassarius arcularia arcularia (Linnaeus, 1758) Nassarius arcularia plicatus (Röding, 1798)Subspecies brought into synonymy Nassarius arcularius arcularius (Linnaeus, 1758) accepted as Nassarius arcularia arcularia (Linnaeus, 1758)↑ 1.0 1.1