Olivella (gastropod)
[2] Adults in the Olivella species are usually quite small, hence the genus has the common name "dwarf olive".The shell of Olivella usually has a keel-like twist at the anterior end of the columella.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.The inner lip is simple posteriorly, regularly and closely plicate at the fore part of the columella.The inner lip has a large, thickened callus, produced at the hind part, and covering and concealing the spire.