''Phorcus richardi'' 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 ...

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

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 Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

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.

Description

The length of the shell varies between 10 mm and 23 mm. The umbilicate, conoidal shell is olivaceous or yellowish. It is ornamented with obliquely longitudinal tawny stripes. The entire surface is smooth. The conical

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires are ...

is short. The sutures are deeply impressed. The five

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 convex, the last one flattened and sloping around the upper part, and very obtusely subangular around the periphery. The large

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 opt ...

is very oblique. The outer lip is thin, acute, and very narrowly margined with yellow, succeeded by a line of black, within which lies a band (about 2 mm wide) of opaque white. The columella is arcuate above, partly surrounding the umbilicus with a white callus. It is straightened in the middle. The umbilical tract lis arge, white, funnel-shaped, and bounded by a carina.Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
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Distribution

This species occurs in the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

and the

Adriatic Sea The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) to t ...

References

* Payraudeau B. C., 1826: ''Catalogue descriptif et méthodique des Annelides et des Mollusques de l'île de Corse''; Paris pp. 218 + 8 pl. * Risso A., 1826–1827: ''Histoire naturelle des principales productions de l'Europe Méridionale et particulièrement de celles des environs de Nice et des Alpes Maritimes'' Paris, Levrault Vol. 1: XII + 448 + 1 carta

826 Year 826 ( DCCCXXVI) was a common year starting on Monday (link will display the full calendar) of the Julian calendar, the 826th year of the Common Era (CE) and ''Anno Domini'' (AD) designations, the 826th year of the 1st millennium, the 26th ...

Vol. 2: VII + 482 + 8 pl. (fiori) ovembre 1827 Vol. 3: XVI + 480 + 14 pl. (pesci) ettembre 1827 Vol. 4: IV + 439 + 12 pl. (molluschi) ovembre 1826 Vol. 5: VIII + 400 + 10 pl. (altri invertebrati) ovembre 1827 * Anton H. E., 1839: ''Verzeichniss der Conchylien welche sich in der Sammlung von Hermann Eduard Anton befinden''; Halle XVI + 110 p * Bucquoy E., Dautzenberg P. & Dollfus G., 1882–1886: ''Les mollusques marins du Roussillon. Tome Ier. Gastropodes.''; Paris, J.B. Baillière & fils 570 p., 66 pl. * Pallary P., 1912: ''Sur la faune de l'ancienne lagune de Tunis''; Bulletin de la Société d'Histoire Naturelle de l'Afrique du Nord 4(9): 215–228 * Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). ''European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification''. Collection Patrimoines Naturels, 50: pp. 180–213

External links

* {{DEFAULTSORT:Phorcus Richardi richardi Gastropods described in 1826