Odostomia torrita
Odostomia torrita is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.[1][2]
Odostomia torrita | |
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Drawing of a shell of Odostomia torrita | |
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Species: | O. torrita |
Binomial name | |
Odostomia torrita Dall & Bartsch, 1909 | |
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Description
The small, vitreous shell has a very elongate-ovate shape. Its length measures 2 mm. The whorls of the protoconch are smooth, and deeply obliquely immersed in the first of the succeeding turns, above which the tilted edge of the last volution only projects. The 5½ whorls of the teleoconch are slightly rounded, moderately contracted at the periphery and well shouldered at the summit. They are marked by strong axial ribs, of which about 20 occur upon all the whorls. The intercostal spaces are about as wide as the ribs. They are marked between the sutures by four slender spiral cords which pass up on the sides of the ribs but do not cross their summits. On the body whorl the first basal keel falls between the sutures. Here, too, the ribs are rendered slightly tuberculate by the spiral cords. The sutures are strongly marked but not channeled. The periphery of the body whorl is marked by a groove. The base of the shell is somewhat produced. It is marked by twelve slender, spiral cords which are a little wider than the spaces that separate them and become successively narrower and more closely spaced from the periphery to the umbilical area. The spaces between the cords are marked by numerous slender, axial threads. The aperture is pyriform, and slightly effuse anteriorly. The posterior angle is acute. The outer lip is pinched in posteriorly. It is thin, showing the external sculpture within. The columella is stout, strongly reflected anteriorly, and reinforced by the base. It is provided with a weak fold at its insertion. The parietal wall is covered with a strong callus.[3]
Distribution
The type species was found in the Pacific Ocean off Mazatlán, Mexico.
References
- WoRMS (2011). Odostomia torrita Dall & Bartsch, 1909. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=575919 on 2012-01-12
- Keen M. (1971). Sea shells of Tropical West America. Marine mollusks from Baja California to Perú. (2nd edit.). Stanford University Press pp. 1064:
- Dall & Bartsch, A Monograph of West American Pyramidellid Mollusks, United States National Museum Bulletin 68, 1p. 142; 1909