''Iredalea subtropicalis'' is a species of

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

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

Drilliidae The Drilliidae are a Taxonomy (biology), taxonomic family (biology), family of small predatory sea snails with high-spired shells. They are classified as marine (ocean), marine gastropod mollusks in the superfamily Conoidea. This family has no s ...

Description

The length of an adult shell varies between 4.5 mm and 6 mm; its diameter 2.2 mm. (Original description) The narrow, fusiform shell is truncated anteriorly. The aperture measures one-third the length of the shell. The shell contains 9

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 ...

s, of which the

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...

forms four. The whorls are flatly rounded and with an impressed suture. The smooth protoconch is sinusigera in form, the exposed portion of its lower lip concave. The aperture is narrow oblong, obliquely angled behind, truncated in front. The outer lip is thick and smooth within. The anal sinus is deep, separated from the

body whorl The body whorl is part of the morphology of the 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. In gastropods In gastropods, the b ...

by a thick callous ridge. Columella smooth within. The

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...

is short and wide. Sculpture : The shell shows regular low axial ridges, about 15 on the body whorl, slightly constricted at their upper ends near the suture. The ridges extend on to the base of the shell, which at its anterior end has 4 oblique low ridges. The entire surface of shell is smooth and shining. The colour of the protoconch is dark yellow. The shell is white, with a faint brown band, dark in patches, along the lower edge of the whorls, but not reaching the outer lip, where, at its anterior end, two narrow brown bands are very faintly indicated. Oliver, W.R.B. (1915) ''The Mollusca of the Kermadec Islands''. Transactions of the New Zealand Institute, 47, 509–568, pls. 9–12
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Distribution

This species occurs in the demersal zone of the Pacific Ocean off Queensland,

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, New Zealand, Easter Island and the Kermadec Islands.

References

Tucker, J.K. 2004 ''Catalog of recent and fossil turrids (Mollusca: Gastropoda)''. Zootaxa 682:1–1295

External links

* {{DEFAULTSORT:Iredalea Subtropicalis subtropicalis Gastropods described in 1915