''Lodderena formosa'' is a minute

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 ...

micromollusc A micromollusc is a shelled mollusc which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine molluscs, although in addition, numerous species of land snails and freshwater molluscs also ...

, 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 ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

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 ...

.Bouchet, P. (2013). Lodderena formosa Powell, 1930. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=565298 on 2013-11-02

Description

The shell is small and nearly flat, with approximately 2 3/4 whorls. It features three prominent spiral keels that are visible from the front. The uppermost keel defines the almost flat upper surface, while the lowest one marks the base, with a third keel midway between them at the periphery. Additionally, there are fine, close spiral lirae numbering about twenty on the upper surface, along with two intermediate spiral ribs of varying strength both above and below. These ribs are more pronounced near the sutures and the edge of the umbilicus. The suture is deeply channeled, with vertical sides comprising about one-quarter of the shell's major diameter at the base, which measures approximately 1.4 mm. The minimum diameter is 1 mm, and the shell reaches a height of about 0.75 mm. The aperture exhibits considerable variation in its structure. Internally, the peristome forms a smooth, continuous inner ring. In terms of color, the shell appears dull-white, characteristic of specimens that are no longer living.

Distribution

This marine species, first described by A.W.B. Powell in 1930, is endemic to

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. It is a minute sea snail or

, a marine gastropod mollusc in the family ''

''.

References

* Powell A.W.B. (1930) ''New species of New Zealand Mollusca from shallow-water dredgings. Part 2.'' Transactions and Proceedings of the Royal Society of New Zealand 61: 536-546. page(s): 541 * Powell A. W. B., ''New Zealand Mollusca'', William Collins Publishers Ltd, Auckland, New Zealand 1979

formosa Taiwan, officially the Republic of China (ROC), is a country in East Asia. The island of Taiwan, formerly known to Westerners as Formosa, has an area of and makes up 99% of the land under ROC control. It lies about across the Taiwan Strait f ...

Gastropods of New Zealand Gastropods described in 1930 {{Trochoidea-stub