''Trimusculus conicus'' is an air-breathing

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 ...

or false

limpet Limpets are a group of aquatic snails with a conical gastropod shell, shell shape (patelliform) and a strong, muscular foot. This general category of conical shell is known as "patelliform" (dish-shaped). Existing within the class Gastropoda, ...

, a

pulmonate Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...

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 ...

Trimusculidae ''Trimusculus'' is a genus of medium-sized air-breathing sea snails or false limpets, marine pulmonate gastropod molluscs in the family Trimusculidae. ''Trimusculus'' is the only genus in the family Trimusculidae. Trimusculidae, the button sn ...

, the button snails. 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 eastern and southern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, and

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 ...

Powell A. W. B., ''New Zealand Mollusca'', William Collins Publishers Ltd, Auckland, New Zealand 1979 including the

Chatham Islands The Chatham Islands ( ; Moriori language, Moriori: , 'Misty Sun'; ) are an archipelago in the Pacific Ocean about east of New Zealand's South Island, administered as part of New Zealand, and consisting of about 10 islands within an approxima ...

Shell description

The

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

is ovate, conoidal, generally depressed, radiately ribbed,

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 ...

rather posterior. The sculpture consists of about 40 subequal narrowly rounded straight riblets, some of which do not extend to the summit. Concentric growth lines are mostly present, and very often produce prominent ridges. The shell colour is white, light-pinkish towards the margin; the interior is white, the margin light pink. The apex is subcentral to nearly marginal, small and distinctly uncinate in well-preserved specimens; anterior and side slopes convex, posterior slope straight, concave, or lightly convex. The interior is shiny with the adductor-scar and siphonal groove distinctly showing. The margin is very slightly crenulate. * Low form: Length is up to 26 mm, width 22.5 mm, and height 8 mm. * High form: Length is up to 22 mm, width 18.5 mm, and height 15 mm.

References

This article incorporates public domain text from reference. Suter H. 1913
''Manual of the New Zealand Mollusca''
Wellington. {{Taxonbar, from=Q5493128 Trimusculidae Gastropods described in 1967 Taxa named by George French Angas Gastropods of Australia Gastropods of New Zealand Fauna of the Chatham Islands