The insular birddrop or

San Clemente Island San Clemente Island (Tongva: ''Kinkipar''; Spanish: ''Isla de San Clemente'') is the southernmost of the Channel Islands of California. It is owned and operated by the United States Navy, and is a part of Los Angeles County. It is administer ...

blunt-top snail,

scientific name In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''Vertigo clementina'', 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 small, air-breathing

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

, a

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

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

Vertiginidae Vertiginidae, common name the whorl snails, is a family of small, air-breathing land snails, terrestrial pulmonate gastropod molluscs or micromollusks in the superfamily Pupilloidea. Distribution The distribution of the Vertiginidae is in the ...

.''Sterkia clementina''.

NatureServe NatureServe, Inc. is a non-profit organization based in Arlington County, Virginia, United States, US, that provides proprietary wildlife conservation-related data, tools, and services to private and government clients, partner organizations, and ...

Explorer, accessed 1 August 2010. (Incorrectly placed within Chondrinidae in the 2006 IUCN Red List.)MolluscaBase eds. (2023). MolluscaBase. Vertigo clementina. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1431022 on 2023-02-08

Description

(Original description) The shell is very minute, narrowly perforate and cylindrical. It is pale horn colored, transparent, with rather obtuse

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics) A-Bomb Abomination Absorbing Man Abraxas Abyss Abyss is the name of two characters appearing in Ameri ...

. The shell contains 5½

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, regularly increasing and moderately rounded. They contain a rather deep suture. The shell is smooth, with few microscopic striae, somewhat shining. The

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk ...

occupies rather more than two-fifths of the length of the shell and is somewhat ascending to the

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 ...

, with a slight, revolving impression on the middle of its last half, ending at the auricle. There is a very slight, flat, crest-elevation near the margin, only in the lower part. The aperture is lateral, scarcely oblique, subovate with the palatal margin slightly flattened, the upper part of same somewhat sinuous. The peristome is a little expanded with a slightly thickened outer

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 ...

just at the margin. The shell contains six white lamellae: two on the apertural wall, the apertural, typical, and a rather long supra-apertural, ending in a callus at the upper termination of the palatal margin. The horizontal columellar margin is typical. The basal is very small, nodule-like and deep seated. The two palatals are typical, the inferior a little longer.Sterki, V. (1890). A new Pupa. The Nautilus. 4(4): 44, pl. 1, fig. 4
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Distribution

This species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the State of

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, U.S.A. The survival of this species is "near threatened".

References

External links

Vanatta, E. G. (1916). Bifidaria clementina oldroydae, n. var. The Nautilus. 30(4): 48
{{Taxonbar, from=Q946788 clementina Fauna of the United States Gastropods described in 1890