''Clanculus villanus'' is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of sea snail, a marine gastropod

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is es ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Trochidae The Trochidae, common name top-snails or top-shells, are a family of various sized sea snails, marine gastropod molluscs in the subclass Vetigastropoda. This family is commonly known as the top-snails because in many species the shell resembles ...

, the top snails. Clanculus villanus 001

Description

The size of an adult shell varies between 10 mm and 21 mm. It differs from the typical forms of ''Clanculus'' in lacking the strong tooth at the base of the

columella Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire. His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the ...

. The very solid shell has a conical shape. It is cinereous-olive or purplish, lighter beneath, and sparsely dotted with black. The about 6

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane flo ...

s are slightly convex, and spirally lirate. The body whorl is encircled by about 14 granose separated lirae, of which about 6 are on the upper surface, their interstices bearing spiral stripe. The body whorl is obtusely angular at the periphery, slightly convex beneath, a little descending anteriorly. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An ...

is rounded-tetragonal. The outer and basal

lip The lips are the visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be ...

s are plicate within. The columella is as in ''

Clanculus guineensis ''Clanculus guineensis'' is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails. Description The size of the shell varies between 15 mm and 25 mm. The very solid shell has a conical shape. It i ...

'' Gmelin, 1791 but longer. The narrow

umbilicus Umbilicus may refer to: *The navel or belly button *Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy * ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants *Umbilicus urbis Romae The ...

is deep. The parietal wall is slightly calloused and is wrinkled.H. Pilsbry, Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
(described as ''Trochus villanus'')

Distribution

This species occurs in the Atlantic Ocean off

Senegal Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣� ...

and

Gabon Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north ...

References

* Bernard, P.A. (Ed.) (1984). ''Coquillages du Gabon hells of Gabon'. Pierre A. Bernard: Libreville, Gabon. 140, 75 plates pp.

External links

* {{DEFAULTSORT:Clanculus Villanus villanus Gastropods described in 1846 Taxa named by Rodolfo Amando Philippi