''Lissospira'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 ...

s, 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 ...

s 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

This genus was proposed for a group of deepwater species which had been erroneously referred to '' Cyclostrema''. They are small, thin, of rather delicate texture (with the exception of '' Lissospira rarinota''), opaque white, and slightly lustrous. Their shell consists of few 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 forming an elevated

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spire ...

, with a relatively large, prominent nuclear whorl and a large

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 ...

. The suture is deep. The umbilicus is small, deep, and does not show any whorls. 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 ...

is somewhat oblique, circular with a slight sutural angle, and not modified by the body whorl to which the simple, continuous peritreme is but slightly attached. The aperture often has an indistinct thread just within the inner

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 ...

, fading out above and below, so that it extends but about halfway round the aperture. It is much nearer the edge along the columellar margin than at the ends and is evidently to prevent the thin operculum being drawn in too far. The operculum is circular, thin, of a delicate horn color, with a central nucleus. It has about seven whorls, defined by a distinct spiral thread, often showing delicate, microscopic transverse growth lines. The

radula The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters ...

consists of numerous rows of delicate teeth. Each row hasone broad central, or median tooth, with a broad, blunt, delicately serrate, curved tip and on either side four more slender lateral teeth also with blunt, curved, delicately serrate tips, beyond which is a series of numerous, between 30 and 50, long, very slender, somewhat sickle-shaped hooks sometimes with delicately serrate tips.

Species

Species within the genus ''Lissospira'' include: * '' Lissospira abyssicola'' Bush, 1897 * '' Lissospira bushae'' (Dall, 1927) * ''

Lissospira chalossensis ''Lissospira'' is a genus of sea snails, marine (ocean), marine gastropod mollusks in the family (biology), family Skeneidae. Description This genus was proposed for a group of deepwater species which had been erroneously referred to ''Cyclostre ...

'' Lozouet, 1999 * '' Lissospira conica'' (Dall, 1927) * '' Lissospira convexa'' Bush, 1897 * '' Lissospira dalli'' (A. E. Verrill, 1882) * '' Lissospira depressa'' (Dall, 1927) * '' Lissospira grata'' Thiele, 1925 * '' Lissospira larva'' Lozouet, 1999 * '' Lissospira ornata'' (A. E. Verrill, 1884) * '' Lissospira proxima'' Tryon, 1888 * '' Lissospira rarinota'' Bush, 1897 * '' Lissospira striata'' Bush, 1897 * '' Lissospira valvata'' (Dall, 1927) ; Species brought into synonymy : * ''Lissospira basistriata'' (Jeffreys, J.G., 1877): synonym of '' Skenea basistriata'' (Jeffreys, J.G., 1877) * ''Lissospira bithynoides'' (Jeffreys, 1883): synonym of '' Lissomphalia bithynoides'' (Monterosato, 1880) * ''Lissospira bujnitzkii'' (Gorbunov, 1946): synonym of '' Leptogyra bujnitzkii'' (Gorbunov, 1946) (new combination) * ''Lissospira ossiansarsi'' Warén, A., 1991: synonym of '' Skenea ossiansarsi'' Warén, 1991 * ''Lissospira profunda'' (Friele, 1879): synonym of '' Skenea profunda'' (Friele, 1879) * ''Lissospira turgida'' (Odhner, 1912): synonym of '' Skenea turgida'' (Odhner, 1912)

References

{{Taxonbar, from=Q6559217 Skeneidae Gastropod genera