Velutina is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of sea snail

Sea snail

Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....

s, a marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 gastropod mollusks in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Velutinidae

Velutinidae

Velutinidae is a family of small sea snails, marine gastropod molluscs in the clade Littorinimorpha.- Taxonomy :The following two subfamilies have been recognized in the taxonomy of Bouchet & Rocroi :* subfamily Velutininae J. E...

.

Species

Species within the genus Velutina include:

• Velutina coriacea (Pallas, 1788)
• Velutina cryptospira Middendorff, 1848
• Velutina plicatilis
  Velutina plicatilis
  Velutina plicatilis is a species of small sea snail, a marine gastropod mollusk in the family Velutinidae.-Distribution:The distribution of Velutina plicatilis is circumboreal...
  
  (O. F. Müller, 1776)
• Velutina pulchella Derjugin, 1950
• Velutina schneideri
  Velutina schneideri
  Velutina schneideri is a species of small sea snail, a marine gastropod mollusk in the family Velutinidae....
  
  Friele, 1886
• Velutina tarasovi Derjugin, 1950
• Velutina velutina
  Velutina velutina
  Velutina velutina, common name the smooth lamellaria, is a species of small sea snail with a transparent shell, a marine gastropod mollusk in the family Velutinidae.-Description:...
  
  (O. F. Müller, 1776)

Species brought into synonymy :

• Velutina beringensis Derjugin, 1950 : synonym of Cartilagovelutina beringensis (Derjugin, 1950)
• Velutina bifasciata Derjugin, 1950 : synonym of Limneria undata (T. Brown, 1839)
• Velutina canaliculata Kröyer, 1847 : synonym of Limneria undata (T. Brown, 1839)
• Velutina capillata Derjugin, 1950 : synonym of Ciliatovelutina capillata (Derjugin, 1950)
• Velutina capuloidea Blainville, 1824 : synonym of Velutina velutina (O. F. Müller, 1776)
• Velutina chondrina Bartsch in Derjugin, 1950 : synonym of Cartilagovelutina chondrina (Bartsch in Derjugin, 1950)
• Velutina conica Dall, 1886 : synonym of Velutina prolongata Carpenter, 1864
• Velutina cristata Derjugin, 1950 : synonym of Cartilagovelutina cristata (Derjugin, 1950)
• Velutina derjugini Bartsch in Derjugin, 1950 : synonym of Velutina prolongata Carpenter, 1864
• Velutina flexilis (Montagu, 1808) : synonym of Velutina plicatilis (O. F. Müller, 1776)
• Velutina fraudatrix Golikov & Kussakin, 1962 : synonym of Velutina tarasovi Derjugin, 1950
• Velutina glabrata Golikov & Kussakin, 1962 : synonym of Velutina coriacea (Pallas, 1788)
• Velutina haliotidea (Fabricius, 1780) : synonym of Velutina velutina (O. F. Müller, 1776)
• Velutina insculpta Odhner, 1913 Limneria insculpta (Odhner, 1913)
• Velutina laevigata "(O. F. Müller, 1777)": synonym of Velutina velutina (O. F. Müller, 1776)
• Velutina lanata Derjugin, 1950 : synonym of Ciliatovelutina lanata (Derjugin, 1950)
• Velutina lanigera Møller, 1842 : synonym of Ciliatovelutina lanigera (Møller, 1842)
• Velutina litoralis Golikov & Kussakin, in Golikov & Scarlato, 1967 : synonym of Velutina coriacea (Pallas, 1788)
• Velutina nana Derjugin, 1950 : synonym of Ciliatovelutina nana (Derjugin, 1950)
• Velutina ochotensis Derjugin, 1950 : synonym of Limneria undata (T. Brown, 1839)
• Velutina pellucida Derjugin, 1950 : synonym of Velutina coriacea (Pallas, 1788)
• Velutina prolongata Carpenter, 1864 : synonym of Limneria prolongata (Carpenter, 1864)
• Velutina rupicola Conrad, 1831 : synonym of Velutina velutina (O. F. Müller, 1776)
• Velutina schantarica Derjugin, 1950 : synonym of Velutina cryptospira Middendorff, 1848
• Velutina sitkensis A. Adams, 1853 : synonym of Velutina plicatilis (O. F. Müller, 1776)
• Velutina striata Macgillivray, 1843 : synonym of Velutina velutina (O. F. Müller, 1776)
• Velutina undata Smith J., 1839: synonym of Limneria undata (T. Brown, 1839)
• Velutina ventricosa Golikov, in Golikov & Scarlato, 1985 : synonym of Velutina coriacea (Pallas, 1788)
• Velutina vulgaris Fleming, 1820 : synonym of Velutina velutina (O. F. Müller, 1776)
• Velutina zonata Gould, 1841 : synonym of Limneria undata (T. Brown, 1839)

Description

The shell

Gastropod shell

The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

 is thin, mostly external, calcareous, auriform, paucispiral and invested by a velvety epidermis

Epidermis (zoology)

The Epidermis is an epithelium that covers the body of an eumetazoan . Eumetazoa have a cavity lined with a similar epithelium, the gastrodermis, which forms a boundary with the epidermis at the mouth.Sponges have no epithelium, and therefore no epidermis or gastrodermis...

. The spire

Spire (mollusc)

A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...

 is lateral and diminutive. The suture is well impressed. The aperture

Aperture (mollusc)

The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

 is very large and rounded with the thin, almost continuous lip. The columellar lip is a little reflected. There is no operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

 or umbilicus.

The oval animal is convex above and little spiral. It has a large oblong foot. The margin of the mantle

Mantle (mollusc)

The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...

 is developed and more or less reflected over the edge of the shell. The head is broad and depressed. The two large tentacle

Tentacle

A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...

s are subulate, blunt, far apart, with eyes sessile on prominences at their outer bases.. The mouth has a short tube.

The formula of the radula

Radula

The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...

 is 2·1·1·1·2. The central tooth is subquadrangular, multicuspid; the central cusps are very long and sharp; lateral teeth are multicuspid, marginals are narrow, with a few obsolete denticles on the margin.

Species in the genus Velutina resemble the pulmonate genus Otina, but Velutina are strictly marine. Sometimes they are met far out at sea, but usually live among stones near low-tide.