Alvania pinguis
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| Alvania pinguis | |
|---|---|
 | |
| Shell of Alvania pinguis (specimen at the Museum of New Zealand) | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Order: | Littorinimorpha |
| Superfamily: | Rissooidea |
| Family: | Rissoidae |
| Genus: | Alvania |
| Species: | A. pinguis |
| Binomial name | |
| Alvania pinguis (W. H. Webster, 1906) | |
| Synonyms | |
| |
Alvania pinguis is a species of small sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae.[1]
The length of the shell attains 2 mm, its diameter 1.25 mm.
(Original description) The white shell consists of 4½ rounded but slightly flattened whorls, of which a very glossy protoconch occupies the first one and a half.
Sculpture: Fine spiral lines, three on the third and four on the body whorl above the aperture. The spirals are crossed by close-set longitudinal ribs as strong as the spirals. They die out on a level with, the posterior angle of the aperture, and the base has three spirals only. The columella is vertically arcuated. The aperture is diagonal-oval, a little angled where the outer lip joins the columella, behind which is a deep groove. The outer lip is thickened externally, especially where it joins the body whorl.[2]
