''Seguenzia cervola'' is a
species of extremely small deep-water
sea snail
Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...
, a
marine
Marine is an adjective meaning of or pertaining to the sea or ocean.
Marine or marines may refer to:
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gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...
mollusk in the
family Seguenziidae
Seguenziidae is a family of very small deepwater sea snails, marine gastropod mollusks in the superfamily Seguenzioidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).Bouchet, P. (2012). Seguenziidae. Accessed through ...
.
[Rosenberg, G. (2013). ''Seguenzia cervola'' Dall, 1919. Retrieved through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=492451 on 2013-06-10]
Description
(Original description by W.H. Dall) The height of the shell attains 4.5 mm. The white shell is small and slightly depressed. It has one small, smooth nuclear
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).
Whorls in nature
File:Photograph and axial plane floral ...
and five subsequent whorls. These are flattened a little in front of a distinct
suture. They are separated by a somewhat convex smooth fasciole from a thread-like keel above the periphery. In front of this is a wide, smooth interval. On the base of the shell are about a dozen spiral threads with
wider interspaces, and very faint microscopic spiral striae are visible in all the interspaces under a lens. On the upper whorls, there is a small thread between the keel and the suture. Near the
apex, they become obsolete. At the
aperture, is a shallow sulcus between the keel and the suture and a smaller one at the middle of the base. There is a sharp notch below the end of the thin, arcuate projecting
columella, behind which is a moderately large twisted
umbilicus. The body shows no glaze. The base of the shell is conspicuously convex.
Dall (1919) Descriptions of new species of Mollusca from the North Pacific Ocean; Proceedings of the U.S. National Museum, vol. 56 (1920)
/ref>
Distribution
The type specimen of this marine species was found off the Coronado Islands, Baja California.
References
External links
Biodiversity Heritage Library (2 publications)
Encyclopedia of Life
USNM Invertebrate Zoology Mollusca Collection
ITIS
World Register of Marine Species
Encyclopedia of Life
USNM Invertebrate Zoology Mollusca Collection
World Register of Marine Species
{{Taxonbar, from1=Q3709825, from2=Q14326692
cervola
Gastropods described in 1919