''Cirsonella gaudryi'' is a
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
sea snail
Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...
, a marine
gastropod
Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, freshwater, and fro ...
mollusk
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...
in the
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Skeneidae
The Skeneidae are a speciose family of minute to small marine gastropod molluscs in the superfamily Trochoidea.Bouchet, P.; Gofas, S. (2013). Skeneidae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.ph ...
.
Description
The height of the shell attains 2.5 mm. The rather solid, shining, white shell has a turbinate shape. it has a narrow
umbilicus
Umbilicus may refer to:
*The navel or belly button
*Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy
*Umbilicus (plant), ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants
*Umbilicus ...
. The spire consists of 3½ convex
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).
In nature
File:Photograph and axial plane floral diagra ...
s, separated by a marked
suture. The surface is smooth, except for the base which contains two or three very faint concentric striae. The circular
aperture
In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...
has a continuous
peristome
Peristome (from the Greek language, Greek ''peri'', meaning 'around' or 'about', and ''stoma'', 'mouth') is an anatomical feature that surrounds an opening to an organ or structure. Some plants, fungi, and shelled gastropods have peristomes.
In mo ...
. The columella has a thick callus that connects to the convexity of the penultimate whorl. it covers for the greater part the
umbilicus
Umbilicus may refer to:
*The navel or belly button
*Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy
*Umbilicus (plant), ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants
*Umbilicus ...
, that is reduced to a narrow, arched chink. The
lip
The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...
is simple.
Dautzenberg P. & Fischer H. (1896). Dragages effectués par l'Hirondelle et par la Princesse Alice 1888–1895. 1. Mollusques Gastropodes.; Mémoires de la Société Zoologique de France 9: 395–498, pl. 15–22
/ref>
Distribution
This species occurs in the Atlantic Ocean
The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...
off the Azores
The Azores ( , , ; , ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atl ...
and the Rockall Bank
Rockall () is a high, uninhabitable granite islet in the North Atlantic Ocean. It is west of Soay, St Kilda, Scotland; northwest of Tory Island, Republic of Ireland, Ireland; and south of Iceland.
The nearest permanently inhabited place is ...
, in the Northeast Atlantic Ocean
The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...
References
External links
*
{{DEFAULTSORT:Cirsonella Gaudryi
gaudryi
Gastropods described in 1896