''Pusionella compacta'' 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 ...

Clavatulidae.

Description

The shell grows to a length of 26 mm. (Original description) This form differs from the group of ''

Clavatula milleti ''Clavatula milleti'' is a species of sea snail, a marine gastropod mollusk in the family Clavatulidae. Description The size of an adult shell varies between 15 mm and 55 mm. The color of the shell is whitish, or yellowish flesh-c ...

'' (synonym: ''Pusionella milleti'') in her characteristic feature of the

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

: the continuous vertical spiral suture is missing. They occur only up to the 7th whorl yet and then disappear completely, and as otherwise deviations also occur, so this form must be singled out. The compact spire contains 11–12

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. These are slightly rounded and convex. 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 the same as in ''Clavatula milleti''. The callus at the anal sinus stands out clearly.H. Strebel, Beiträge zur Kenntnis der Meeresfauna Westafrikas; bd. 1 (1914–1915)
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Distribution

This species occurs in the Atlantic Ocean off

West Africa West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Mau ...

and

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

References

External links

*
Specimen in the MNHN, Paris
{{DEFAULTSORT:Pusionella Compacta compacta Gastropods described in 1914