''Clanculus guineensis'' is a

species In biology, a species is the basic unit of 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 the appropriate s ...

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 e ...

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 resemb ...

, 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 is, rather depressed, angulate at the periphery and deeply umbilicate. Its color is whitish, painted with broad radiating purplish brown stripes above. The base of the shell shows narrow radiating stripes or tessellations of the same shade. The about six

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 floral ...

s are planulate or slightly concave above. The whitish

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics), a teenaged super villainess in the Marvel Universe * Ape-X, a super-intelligent ape in the Squadron Supreme universe *Apex, ...

is eroded. The succeeding whorls are spirally beaded. The body whorl slightly descends anteriorly, bearing on the upper surface about 7 spiral beaded lirae. The interstices are obliquely finely striate. The base is subplanulate, concentrically sculptured with about 7 or 8 beaded lirae. The rounded

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 rhomboidal. 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 thick, evenly and finely plicate within. 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 wo ...

is oblique, deeply entering, conspicuously fielded near its insertion. Its edge is denticulate near the base, and passing into the basal margin with a regular curve. The parietal wall bears a white wrinkled callus, the umbilical margin of which is dentate. The wide umbilicus is deep, scarcely narrowed as it penetrates, bordered by a strong acutely dentate rib. It differs from the typical forms of ''Clanculus'' in lacking the strong tooth at the base of the columella.H. Pilsbry, Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
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Distribution

This species occurs in the Atlantic Ocean off

Angola , national_anthem = " Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

, the Ivory Coast 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 nort ...

References

* Gofas, S.; Afonso, J.P.; Brandào, M. (Ed.). (S.a.). ''Conchas e Moluscos de Angola = Coquillages et Mollusques d'Angola. hells and molluscs of Angola'' Universidade Agostinho / Elf Aquitaine Angola: Angola. 140 pp.

External links

* {{DEFAULTSORT:Clanculus guineensis guineensis Gastropods described in 1791