Coelotrochus oppressus

Coelotrochus oppressus
Drawing of a shell of Coelotrochus oppressus
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Clade: Vetigastropoda
Superfamily: Trochoidea (superfamily)
Family: Trochidae
Genus: Coelotrochus
Species: C. oppressus
Binomial name
Coelotrochus oppressus
(Hutton, 1878) [1]
Synonyms[2]
  • Gibbula oppressa Hutton, 1878 (original description)
  • Thoristella oppressa (Hutton,1878)
  • Trochus oppressus Hutton, 1878

Coelotrochus oppressus, common name the shouldered top shell, is a species of very small sea snail, a marine gastropod mollusc in the family Trochidae, the top snails or top shells.[2]

Description

The length of the shell attains 5.5 mm, its diameter 6 mm. The small, somewhat solid shell has a conical shape. It is lustreless, with a false umbilicus. The sculpture of the entire surface is closely finely spirally striate. The striae of the base become coarser toward the axis. The colour of the shell is dark olive-brown or greenish, minutely tessellated all over with a slightly darker shade of the same hue. The small protoconch is conical with two slightly spirally striated whorls. The teleoconch consists of five whorls, those of the spire keeled above the middle. The body whorl is biangular. The base of the shell is rather flattened. The suture is slightly impressed. The oblique aperture is subquadrangular, iridescent and slightly lirate within. The peristome is sharp and discontinuous. The outer and basal lip are convex, with a narrow opaque margin within, which is smooth. The oblique columella is straight, in adult specimens with a few inconspicuous plications above. The umbilicus is filled with callus, leaving only a slight pit. [3]

Distribution

This marine species is endemic to New Zealand and occurs off North Island

External links

References

  1. Hutton., J. de Conch., xxvi, 1878, 34
  2. 1 2 Rosenberg, G. (2012). Coelotrochus oppressus. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=598201 on 2012-06-21
  3. Suter H. (1913-1915), Manual of New Zealand Mollusca; Wellington, N. Z. :J. Mackay, govt. printer,1913-1915 (described as Trochus oppressus)
This article is issued from Wikipedia - version of the Wednesday, June 04, 2014. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.