Ethalia is a genus of sea snails, marine gastropod mollusks in the subfamily Umboniinae of the family Trochidae, the top snails.[2]

Ethalia
Two views of a shell of Ethalia sanguinea
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Vetigastropoda
Order: Trochida
Superfamily: Trochoidea
Family: Trochidae
Genus: Ethalia
H. Adams & A. Adams, 1854 [1]
Type species
Rotella guamensis
Quoy & Gaimard, 1834
Synonyms
  • Teinostoma (Ethalia) H. Adams & A. Adams, 1854 superseded rank
  • Trochus (Liotrochus) P. Fischer, 1878 junior subjective synonym
  • Umbonium (Ethalia) H. Adams & A. Adams, 1854

Description

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The species are moderate-sized. The orbicular shell is turbinately depressed. The whorls are convex, smooth or transversely striated, the last one rounded at the periphery. They have a mottled or streaked color-pattern. The umbilicus is partly closed by a callus deposit. The columellar lip ends anteriorly in an obtuse dilated callus. The callus emitted at the columellar-parietal angle of the aperture is tongue-shaped, closing the umbilicus except a rather narrow chink, or even entirely, in some species.[3]

(More recent description) The shell is relatively large for the subfamily Umboniinae (up to 25 mm in diameter); It is lenticular, globose-lenticular, or subglobose; the surface is smooth and glossy, or dull with fine, closely spaced spiral lirae; the axial sculptureis weak or nearly obsolete. The umbilicus is usually present, commonly bordered by a thickened rim and variably obstructed by a callus deposition associated with the umbilical funicle and parietal lip. The outer lip is simple, with a smooth inner surface lacking denticles or lirae. The operculum is corneous, thick, multispiral but only loosely coiled; whorl overlap narrow, the peripheral fringe is scarcely developed, and spiral microsculpture is absent. The radula is with relatively robust base-plates on both the rachidian and lateral teeth; inner marginal tooth transitional, bearing a reduced terminal cusp. Outer marginal teeth with 3–10 principal cusps, dominated by a large, bluntly lanceolate central denticle that is flanked basally on its outer side by one or two smaller accessory denticles. The ctenidium is bipectinate, with the anterior portion remaining free. [4]

Distribution

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This marine genus occurs in the Central and East Indian Ocean, off East Africa, off Indo-Malaysia, and off Australia.

Species

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Species within the genus Ethalia include:

Species brought into synonymy

References

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  • Wilson, B., 1993. Australian Marine Shells. Prosobranch Gastropods. Odyssey Publishing, Kallaroo, WA
  • Higo, S., Callomon, P. & Goto, Y. (1999) Catalogue and Bibliography of the Marine Shell-Bearing Mollusca of Japan. Elle Scientific Publications, Yao, Japan, 749 pp.
  • Williams S.T., Karube S. & Ozawa T. (2008) Molecular systematics of Vetigastropoda: Trochidae, Turbinidae and Trochoidea redefined. Zoologica Scripta 37: 483–506.
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