Nanula tasmanica

Nanula tasmanica is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails

Nanula tasmanica
Drawing with an apertural view of a shell of Nanula tasmanica
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Vetigastropoda
Order:	Trochida
Superfamily:	Trochoidea
Family:	Trochidae
Genus:	Nanula
Species:	N. tasmanica
Binomial name
Nanula tasmanica (Petterd, 1879)
Synonyms
Calliotrochus tasmanicus May, W.L. 1923 Gibbula tasmanica Petterd, 1879

Description

The height of the shell attains 6 mm, its diameter 5.5 mm. The small, rather thin, perforate shell has a globose-turbinate shape. It is lusterless, whitish, tinged with yellow or greenish, unicolored or marked with a few angular radiating maculations of blackish-brown. The spire is very short. The sutures are impressed. The about 4½ whorls are convex, rounded, all over finely regularly spirally lirulate. The body whorl is rounded at the periphery, or very bluntly subangular. It is convex beneath and impressed around the umbilicus. The aperture is quite oblique, rounded-ovate, angular above, broadly rounded below, with a thin iridescent layer of nacre within. The outer, basal and columellar margins are rather thin, curved, the latter joined to the upper margin by a thin white parietal callous. The narrow umbilicus is not bounded by an angle.

This dull whitish little shell may be known by its finely striate surface, narrow umbilicus, short spire and globose-turbinate form.

Distribution

This marine species is endemic to Australia and occurs in the shallow subtidal zone off Tasmania, Victoria and in the Bass Strait.

References

• Petterd, W. 1879. New species of Tasmanian marine shells. Journal of Conchology 2: 102–105
• May, W.L. 1923. An Illustrated Index of Tasmanian Shells. Hobart : Government Printer 100 pp.

External links

• "Nanula tasmanica". Gastropods.com. Retrieved 16 January 2019.