Alvania verconiana is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae.[1]
Alvania verconiana | |
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Shell of Alvania verconiana (holotype) | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Subclass: | Caenogastropoda |
Order: | Littorinimorpha |
Superfamily: | Rissooidea |
Family: | Rissoidae |
Genus: | Alvania |
Species: | A. verconiana
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Binomial name | |
Alvania verconiana (Hedley, 1911)
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Synonyms | |
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Description
editThe length of the shell attains 2 mm, its diameter 1.25 mm.
(Original description) The small shell is ovate, thin and translucent. Its colour is white. It contains four rounded whorls, parted by deep sutures.
Sculpture: First whorl and a half are smooth The next show about twenty-five sharp though delicate radial ribs. These increase towards the body whorl. They amount to about forty. Below the periphery they fade gradually. Different individuals vary in the development and number of these radials. On the body whorl there are eight or ten spirals equal in grade to the radials that override them, thus enclosing rectangular meshes. On the upper whorls the spirals gradually vanish, so that on the base are spirals alone and on the upper whorls radials alone. A secondary microscopic sculpture of close spiral scratches is most conspicuous in the meshes of the body whorl.
The aperture is subcircular and angled above. The outer lip is fortified by a slight external varix. The columella margin is expanded and reflected over a small umbilical furrow. [2]
Distribution
editThis marine species is endemic to Australia and occurs off South Australia and Western Australia.
References
edit- ^ MolluscaBase eds. (2024). MolluscaBase. Alvania verconiana (Hedley, 1911). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=594882 on 2024-01-31
- ^ Hedley, C. (1911). Report on the Mollusca obtained by the F.I.S. "Endeavour", chiefly off Cape Wiles, South Australia. Part I. in: Zoological Results of the Fishing Experiments carried out by F.I.S. "Endeavour" 1909-10 under H. C. Dannevig, Commonwealth Director of Fisheries, volume 1: 90-114, pls 17-20 This article incorporates text from this source, which is in the public domain.
- Ponder, W.F. 1985. A review of the genera of the Rissoidae (Mollusca: Mesogastropoda: Rissoacea). Records of the Australian Museum suppl. 4: 1-221