Olivella shell
| Olivella | |
|---|---|
 |
|
| A live individual of Olivella biplicata with its pale siphon showing at the front and the very long, rather dark, posterior mantle tentacle laid back against the upper surface of the shell | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| (unranked): |
clade Caenogastropoda clade Hypsogastropoda |
| Superfamily: | Olivoidea |
| Family: | Olivellidae |
| Genus: |
Olivella Swainson, 1831 |
clade Hypsogastropoda
clade Neogastropoda
Olivella, common name the dwarf olives, is a genus of small predatory sea snails, marine gastropod molluscs in the family Olivellidae, the dwarf olives. Olivella is the type genus of the family.
Adults in the Olivella species are usually quite small, hence the genus has the common name "dwarf olive". Species of Oliva are usually larger, but there are exceptions.
The shell of Olivella usually has a keel-like twist at the anterior end of the columella. The wall above it may be concave or have deep furrows. The inner lip can sometimes show a deep callus, and in many cases this extends over the parietal wall to the end of the aperture. This callus formation may extend to the spire but leave the suture open. Most species of Olivella have a thin, chitinous operculum, but this operculum is lacking in Olivella nivea, as is also the case in species of Oliva.
Species in the genus Olivella include:
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