{{Short description|Genus of gastropods}} {{About|the genus of sea snails|the botanical journal|Addisonia (journal)}} {{Automatic taxobox | taxon = Addisonia | image = Addisonia excentrica 001.jpg | image_caption = Drawing of three views of ''Addisonia excentrica'' | authority = Dall, 1882<ref>Dall (1882). ''Proc. U.S. nat. Mus.'' '''4''': 405.</ref> | synonyms_ref = | synonyms = | display_parents = 3 }}

'''''Addisonia''''' is a genus of sea snails, marine gastropod mollusks in the family Addisoniidae.<ref name="WoRMS">{{WRMS species|137625|''Addisonia'' Dall, 1882||30 January 2011}}</ref>

==Description== The ovate shell has a subconical shape. It is strongly symmetrical, porcellaneous, and thin. The blunt apex is curved backward, downward, and to the left. The shell has no epidermis. The margin is unthickened, simple, and entire. The pedal muscular impression is horseshoe-shaped and interrupted in front.

The radula has a large simple rhachidian tooth with, on each side, two large, simple transverse laterals, followed by two minute ones, and a large outer lateral with a strong tridentate cusp, outside of which is a single scale-like flat uncinus, bearing an elongated thickened ridge, but no cusp.

Soft parts : the head is provided with two tentacles without eyes or eye tubercles. The muzzle is plain and simple. The foot is thin, orbicular, without lateral or posterior tubercles, processes or fringes. The mantle edge is simple and thickened. The gill is composed of leaflets as in ''Patella'', the series starting on the right behind the head and continued within the mantle edge backward. The body of the animal is asymmetrically placed with regard to the aperture of the shell to afford room for the enormous series of branchial leaflets. The anus opening is behind and above the head slightly to the right of the median line, and indicated by a small papilla.<ref>[https://archive.org/stream/manualconch12tryorich/manualconch12tryorich_djvu.txt G.W. Tryon (1889), Manual of Conchology vol. 12 p. 139]</ref>

==Species== Species within the genus ''Addisonia'' include: * ''Addisonia brophyi'' McLean, 1985<ref>{{WRMS species|451664|''Addisonia brophyi'' McLean, 1985||11 April 2010}}</ref> * ''Addisonia excentrica'' (Tiberi, 1855)<ref>{{WRMS species|138699|''Addisonia excentrica'' (Tiberi, 1855)||11 April 2010}}</ref> ; Species brought into synonymy : * ''Addisonia enodis'' Simone, 1996 : synonym of ''Addisonia excentrica'' (Tiberi, 1855) * ''Addisonia lateralis'' (Requien, 1848):<ref>{{WRMS species|451662|''Addisonia lateralis'' (Requien, 1848)||11 April 2010}}</ref> synonym of ''Addisonia excentrica'' (Tiberi, 1855) * ''Addisonia paradoxa'' Dall, 1882:<ref>{{WRMS species|451661|''Addisonia paradoxa'' Dall, 1882||25 October 2010}}</ref> synonym of ''Addisonia excentrica''

==References== {{Reflist}} * Mc Lean J. H. (1985). ''The Archaeogastropod Family Addisoniidae Dall, 1882: life habit and review of species''. The Veliger 28 (1): 99-108 [details] * Roldan E. & Luque A. (2010) ''The ecology, biology and taxonomy of Addisonia excentrica (Tiberi, 1855) (Cocculiniformia: Addisoniidae) from southern Spain''. Journal of Molluscan Studies 76:201-210.

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Category:Addisoniidae Category:Taxa named by William Healey Dall