Odostomia exarata is a species of sea snail, a marine gastropod mollusc in the family Pyramidellidae, the pyrams and their allies.[2][3]
| Odostomia exarata | |
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| Aperturtal view of the shell of Odostomia exarata | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Family: | Pyramidellidae |
| Genus: | Odostomia |
| Species: | O. exarata
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| Binomial name | |
| Odostomia exarata | |
| Synonyms | |
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Description
editThe elongate-ovate shell is white. Its length is 6.3 mm. The whorls of the protoconch are obliquely immersed, with only the tilted edge of the last volution visible. The five whorls of the teleoconch are marked by two spiral keels which divide the space between the sutures into three equal parts. The posterior of these keels shows weak crenulation. The periphery of the body whorl is marked by a third keel which is almost as strong as those on the spire. A fourth keel, which is considerably less strong, occupies the middle of the base. The rounded spaces between the keels are marked by feeble lines of growth. The aperture is irregularly oval. The posterior angle is obtuse. The outer lip is angulated by the keels. The columella is strong, reflected, and provided with a weak fold at insertion. The parietal wall is covered with a thin callus.[4]
Distribution
editThis species occurs in the Pacific Ocean off the Galapagos Islands. The type specimen was found offMazatlán, Mexico.
References
edit- ^ Carpenter, Cat. Mazatlan Shells, 1856, pp. 115
- ^ WoRMS (2011). Odostomia exarata Carpenter, 1857. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=575843 on 2011-11-10
- ^ Keen M. (1971). Sea shells of Tropical West America. Marine mollusks from Baja California to Perú. (2nd edit.). Stanford University Press pp. 1064:
- ^ "A Monograph of West American Pyramidellid Mollusks", William Healy Dall and Paul Bartsch, Smithsonian Institution, 1909]
- Finet, Y. (2001) The marine mollusks of the Galapagos Islands: a documented faunal list. Editions du Muséum d' Histoire naturelle, Genève, 237 pp.