Zebinella janus

Zebinella janus
Shell of Zebinella janus (holotype)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Littorinimorpha
Superfamily:	Rissooidea
Family:	Rissoinidae
Genus:	Zebinella
Species:	Z. janus
Binomial name
Zebinella janus (C. B. Adams, 1852)
Synonyms [1]
Rissoa janusC. B. Adams, 1852 (basionym) Rissoina janus(C. B. Adams, 1852)

Zebinella janus is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoinidae. ^[1]

Description

(Original description) The white shell is long and ovate conic. Anteriorly it is covered with fine crowded spiral striae. Elsewhere it is covered with small crowded transverse ribs, which on the body whorl appear merely as transverse stria becoming obsolete near the periphery. The apex is acute. The outlines of the spire are moderately curvilinear. It contains nine whorls, moderately convex, with a lightly impressed suture. The aperture is large, oblique, moderately effuse below, more deeply effuse above. The outer lip is much advanced along the middle, thickened by a broad stout varix. The umbilicus is wanting. ^[2]

The type of Z. janus in the Amherst collection, collected by C. B. Adams, at Panama, is a very badly worn medium sized shell, in which the ribs have been worn down to such an extent that one can scarcely count them. There are probably 20 on each of the last 2 whorls. It is absolutely impossible to decide whether spiral sculpture may have been present or absent. ^[3]

Distribution

This marine species occurs off Panama, Caribbean Sea.

References

1. MolluscaBase eds. (2023). MolluscaBase. Zebinella janus (C. B. Adams, 1852). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=767541 on 2023-10-25
2. Adams, C. B. (1852). Catalogue of shells collected at Panama, with notes on their synonymy, station, and habitat. Annals of the Lyceum of Natural History of New York. 5: 229-549
3. Turner, R. D. (1956). The Eastern Pacific marine mollusks described by C. B. Adams. Occasional Papers on Mollusks, Museum of Comparative Zoology. 2(20): 21-135

• Faber M.J. & Moolenbeek R.G. (2013) Two new species of Rissoinidae from Guadeloupe (Gastropoda: Rissooidea). Miscellanea Malacologica 6(1): 9-14

External links

• Bartsch, P. (1915). The Recent and fossil mollusks of the genus Rissoina from the west coast of America. Proceedings of the United States National Museum. 49 (2094): 33-62, plates 28-33