Odostomia lapazana

Odostomia lapazana
Apertural view of the shell of Odostomia lapazana
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
(unranked): clade Heterobranchia
clade Euthyneura
clade Panpulmonata
Superfamily: Pyramidelloidea
Family: Pyramidellidae
Genus: Odostomia
Species: O. lapazana
Binomial name
Odostomia lapazana
Dall & Bartsch, 1909
Synonyms[1]

Odostomia (Chrysallida) lapazana Dall & Bartsch, 1909

Odostomia lapazana is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.[2][3]

Description

The white shell has a broadly ovate shape. Its length measures 2.8 mm. The whorls of the protoconch are smooth, deeply obliquely immersed in the first of the succeeding turns, above which only the tilted edge of the last volution projects. The five whorls of the teleoconch are moderately contracted at the sutures, strongly slopingly shouldered at the summit, where the angle of the shoulder falls on the second spiral keel. The whorls are marked by well developed, nodulous axial ribs, of which 20 occur upon all the whorls. The intercostal spaces are about twice as wide as the ribs, crossed by five equal spiral cords, which are about half as strong as the ribs and render them nodulous at their junction. The first spiral cord is a little posterior to the middle of the shoulder. The spaces enclosed by the ribs and cords are deep, rectangular pits, the long axis of which coincides with the spiral cords. The sutures are strongly marked, but not channeled. The periphery of the body whorl is marked by a spiral cord to the posterior extremity of which the axial ribs extend, but whose summits they do not cross. The base of the shell is short, well rounded. It is marked by nine spiral keels which are about as wide as the spaces that separate them, decreasing successively in strength and spacing from the periphery to the umbilical area. The grooves between the spiral cords are marked by numerous fine, axial raised threads. The aperture is oval, slightly effuse anteriorly. The posterior angle is obtuse. The outer lip is thin. The columella is slender, strongly reflected and provided with a fold at its insertion. [1]

Distribution

This species occurs in the Pacific Ocean off Lower California.

References

  1. 1 2 W.H. Dall and P. Bartsch, "A Monograph of West American Pyramidellid Mollusks" , Smithsonian Institution, 1909
  2. WoRMS (2011). Odostomia lapazana Dall & Bartsch, 1909. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=575863 on 2011-11-10
  3. Keen M. (1971). Sea shells of Tropical West America. Marine mollusks from Baja California to Perú. (2nd edit.). Stanford University Press pp. 1064:
External identifiers for Odostomia lapazana
WoRMS 575863
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