en Alvania macandrewi

Alvania macandrewi
	Shell of Alvania macandrewi (specimen at the Natural History Museum, Rotterdam)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Littorinimorpha
Family:	Rissoidae
Genus:	Alvania
Species:	A. macandrewi
Binomial name
	Alvania macandrewi; (Manzoni, 1868)
Synonyms
	Rissoa macandrewi Manzoni, 1868 · unaccepted (original combination); Rissoa macandrewi var. spreta R. B. Watson, 1873: synonym of Alvania macandrewi (Manzoni, 1868);

Alvania macandrewi is a species of small sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae.^[1]

Description

The length of the shell varies between 2.4 mm and 3 mm.

In some of its forms A. macandrewi greatly resembles some forms of Alvania canariensis. But the spire rises more in steps, the last three whorls are less attenuated, the ribs are wider-set, are broader, and fewer. The spiral scratchings are much more distinct. The heavy white labial rib and the absence of the brown stain either on this rib or on the tip of the apex are very distinctive. ^[2]

The shell is imperforate, solid and has a yellowish chestnut color. It contains six whorls, turreted or round-shouldered, with close, large, longitudinal ribs, rendered nodulous by spiral impressed lines. The lip is duplicate, the outer lip expanded, with fimbriated edge. ^[3]

Distribution

This species occurs in the Atlantic Ocean off Madeira and the Canary Islands.

References

^ Alvania macandrewi (Manzoni, 1868). Gofas, S. (2009). Alvania macandrewi (Manzoni, 1868). In: Bouchet, P.; Gofas, S.; Rosenberg, G. World Marine Mollusca database. Accessed through the World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=141210 on 9 August 2010 .
^ Watson, R. B. (1873). On some marine mollusca from Madeira, including a new genus of the Muricinae, a new Eulima and the whole of the Rissoa of the group of islands. Proceedings of the Zoological Society of London. 1873: 361-391
^ G.W. Tryon (1884), Manual of conchology, structural and systematic : with illustrations of the species; Academy of Natural Sciences ser. 1, vol. 9 This article incorporates text from this source, which is in the public domain.

External links

[WoRMS-1] Alvania macandrewi (Manzoni, 1868). Gofas, S. (2009). Alvania macandrewi (Manzoni, 1868). In: Bouchet, P.; Gofas, S.; Rosenberg, G. World Marine Mollusca database. Accessed through the World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=141210 on 9 August 2010 .

[2] Watson, R. B. (1873). On some marine mollusca from Madeira, including a new genus of the Muricinae, a new Eulima and the whole of the Rissoa of the group of islands. Proceedings of the Zoological Society of London. 1873: 361-391

[3] G.W. Tryon (1884), Manual of conchology, structural and systematic : with illustrations of the species; Academy of Natural Sciences ser. 1, vol. 9 This article incorporates text from this source, which is in the public domain.

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