Bivetopsia is a genus of sea snails, marine gastropod mollusks in the family Cancellariidae, the nutmeg snails.Bouchet, P. (2012). Bivetopsia Jousseaume, 1887. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=464459 on 2012-08-26
General characteristics (Original description in French) The shell is solid, ovoid in shape, and features a very narrow umbilicus along with a striated and ribbed surface. The spire consists of seven whorls that are distinctly depressed near the suture.
The aperture is oval. The siphonal canal is structured so that it does not notch the peristome, while the anterior canal is short, wide, and deep. The outer lip is ribbed on the inside and becomes broadly depressed toward its anterior third. Along the columellar margin, there are three prominent folds; the posterior fold is positioned just in front of the ridge formed by the siphonal canal. The columellar callus is very thick, strongly striated, and features sharply defined, slightly raised edges.
Species Species within the genus Bivetopsia include: † Bivetopsia charapota (Olsson, 1942) Bivetopsia chrysostoma (G.B. Sowerby I, 1832) Bivetopsia haemastoma (G.B. Sowerby I, 1832) † Bivetopsia herberti (Landau, Petit & C. M. Silva, 2007) † Bivetopsia moorei (Guppy, 1866) † Bivetopsia pachia (M. Smith, 1940) † Bivetopsia plectilis (P. Jung & Petit, 1990) † Bivetopsia pachia (M. Smith, 1940) † Bivetopsia porvenirensis Landau, Petit, Etter & C. M. Silva, 2012 Bivetopsia rugosa (Lamarck, 1822)
References
Hemmen J. (2007). Recent Cancellariidae, Annotated and illustrated catalogue of Recent Cancellariidae. Privately published, Wiesbaden. 428 pp. [With amendments and corrections taken from Petit R.E. (2012) A critique of, and errata for, Recent Cancellariidae by Jens Hemmen, 2007. Conchologia Ingrata 9: 1-8.