Odostomia thea

Odostomia thea
Drawing of a shell of Odostomia thea
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Heterobranchia
Family:	Pyramidellidae
Genus:	Odostomia
Species:	O. thea
Binomial name
Odostomia thea Bartsch, 1912
Synonyms
Odostomia (Evalea) thea Bartsch, 1912

Odostomia thea is a species of sea snail, a marine gastropod mollusc in the family Pyramidellidae, the pyrams and their allies. ^{[1] [2]}

Description

The moderately large, yellowish-white shell has an elongate-ovate shape. Its length measures 4.3 mm. The whorls of the protoconch are small and deeply, obliquely immersed in the first of the succeeding turns, above which only the tilted edge of the last volution projects. The six whorls of the teleoconch are moderately rounded, rather high between the sutures, and slightly shouldered at the summit. They are crossed by numerous fine, decidedly retractive lines of growth. The spiral sculpture is strong on the early whorls, becoming gradually finer with the growth of the shell.

The first two turns are divided into five, almost equal areas by four equally, strongly incised, spiral Iines, between the sutures. On the third whorl the spiral lines are increased to about a dozen and are considerably less strong; on the succeeding turn they are probably almost tripled and still weaker; while on the penultimate volution the sculpture consists of somewhat wavy, closely spaced, spiral striations. The periphery of the body whorl is obscurely angulated, and somewhat inflated. The base of the shell is moderately long, curving gently to the anterior portion of the shell. It is marked like the body whorl with fine, spiral lines. The sutures are somewhat constricted. The oval aperture is moderately large. The posterior angle is obtuse. The outer lip is thin. The inner lip is rather long, slightly curved, and somewhat revolute. It is provided with a strong fold at its insertion. The parietal wall is glazed with a thin callus. ^[3]

Distribution

The type species was found in the Pacific Ocean off San Pedro, California.

References

1. Rosenberg, G. (2011). Odostomia thea Bartsch, 1912. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=581262 on 2012-01-12
2. Turgeon, D.; Quinn, J.F.; Bogan, A.E.; Coan, E.V.; Hochberg, F.G.; Lyons, W.G.; Mikkelsen, P.M.; Neves, R.J.; Roper, C.F.E.; Rosenberg, G.; Roth, B.; Scheltema, A.; Thompson, F.G.; Vecchione, M.; Williams, J.D. (1998). Common and scientific names of aquatic invertebrates from the United States and Canada: mollusks. 2nd ed. American Fisheries Society Special Publication, 26. American Fisheries Society: Bethesda, MD (USA). ISBN   1-888569-01-8. IX, 526 + cd-rom pp.
3. Paul Bartsch, Additions to the West American Pyramidellid Mollusk Fauna with Descriptions of New Species, Proc. U.S. National Museum 42, p. 278; 1912

External links

• To World Register of Marine Species
• To ITIS