Alvania enysii

Alvania enysii
Shell of Alvania enysii
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Littorinimorpha
Superfamily:	Rissooidea
Family:	Rissoidae
Genus:	Alvania
Species:	†A. enysii
Binomial name
†Alvania enysii (Bell, 1898)
Synonyms
† Rissoa enysii Bell, 1898 (Alvania accepted as full genus)

Alvania enysii is an extinct species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae.[1]

Description

The length of the shell attains 6 mm, its diameter 3 mm.

(Original description) The small shell is elongate-conical. It contains 7-8 nearly flat whorls, slightly angulate or constricted immediately below the suture. The spire is regularly tapering to a blunt point. The suture is well marked. The whorls are ornamented by numerous straight ribs which die out on the body whorl. They are hardly extending to the base. The sculpture also shows distinct spiral ridges which are continuous beyond the termination of the ribs. Crossing the latter, they produce a slight tuberculation where they intersect, and are prominent at the base of the shell. The ovate aperture is angulate, and has a small chink above. The outer lip is roundly lunate. The peristome is continuous. The inner lip is slightly deflected in front of a minute perforation. [2]

Distribution

Fossils were found in Pliocene strata off St Erth, Great Britain.

References

1. MolluscaBase eds. (2024). MolluscaBase. Alvania enysii (Bell, 1898) †. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1027569 on 2024-02-13
2. Harmer F. W. (1920-1925). The Pliocene Mollusca of Great Britain, being supplementary to S.V. Wood's monograph of the Crag Mollusca. Vol. 2. Monographs of the Palaeontographical Society. 72(344): 485-652, pl. 45-52 (part 1, December 1920); 73(346): 653-704, pl. 53-56 (part 2, July 1921); 75(352): 705-856, pl. 57-64 (part 3, December 1923); 76(354): i-xiv, 857-900, pl. 65 (part 4, January 1925). This article incorporates text from this source, which is in the public domain.

External links