Ethminolia vitiliginea

Ethminolia vitiliginea
shells of Ethminolia vitiliginea
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Clade: Vetigastropoda
Superfamily: Trochoidea
Family: Trochidae
Genus: Ethminolia
Species: E. vitiliginea
Binomial name
Ethminolia vitiliginea
(Menke, 1843)
Synonyms
  • Ethalia tasmanica Tenison-Woods, J.E., 1877
  • Ethminolia tasmanica Macpherson, J.H. & Gabriel, C.J. 1962
  • Minolia tasmanica Tenison-Woods, 1876
  • Minolia tasmanica Pritchard, 1902
  • Talopena (Ethalia) tasmanica Tenison Woods, 1877
  • Trochus vitiliginea Menke, 1843

Ethminolia vitiliginea, common name the depressed top shell, is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.[1]

Description

The size of an adult shell varies between 7 mm and 11 mm. The broadly umbilicate shell is depressed and has a low-conoidal spire. It is thin, scarcely shining, and opaque whitish. The upper surface shows radiating macalations of purplish or olive-brown. The base of the shell is marbled with the same colors. The minute apex is acute. The sutures are well impressed. The about 5½ whorls are convex, those of the spire subangular in the middle, flattened below the suture, giving the spire a terraced appearance. The body whorl is subcylindrical, obtusely subangular at the periphery, convex beneath. The surface all over is encircled by delicate spiral elevated striae, and around the umbilicus decussated by growth lines. The aperture is subcircular, a trifle modified by the contact of the penultimate whorl. The margins all thin and simple . The umbilicus is about ¼ the diameter of base, opaque white within, and longitudinally striated.

The tubular whorls, rounded save for a flattened area below the suture, and keel-less except for the carina banding that area, will discriminate this shell from many species. Other marks are the delicate spiral striation, wide umbilicus, and broad radiating maculations of the upper surface.[2]

Distribution

This marine species is endemic to Australia and occurs from the Bass Strait to Western Australia.

References

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