Kingdom Animalia Class Gastropoda Family Pyramidellidae Rank Species | Phylum Mollusca Superfamily Pyramidelloidea Genus Odostomia | |
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Odostomia pulcherrima is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.
Contents
Description
The large shell is elongate-oval and vitreous. Its length measures 5 mm. The whorls of the protoconch are small, smooth, deeply obhquely immersed in the first post-nuclear turn, above which only the tilted edge of the last volution projects. The six whorls of the teleoconch are strongly rounded, decidedly contracted at the sutures and strongly shouldered at the summit. The first is marked by four slender spiral cords and numerous exceedingly fine axial threads. The next three have twenty strong, rounded, axial ribs, which terminate at the posterior edge of the fourth keel, leaving this smooth. On the body whorl the ribs are decidedly enfeebled, being replaced by numerous axial threads. The spiral sculpture consists of four strong cords between the sutures, the three which cross the ribs form strong nodules at their junction with them, while the supraperipheral one is smooth. The utures are strongly impressed and slightly channeled. The periphery and the base of the body whorl are well rounded. They are marked by eight spiral keels, which grow successively weaker from the periphery to the umbilical region, the last three being very fine. The spaces separating the cords equal to them,are crossed by numerous slender, axial threads. The aperture is irregularly ovate. The posterior angle is obtuse. The outer lip is strong, rendered decidedly sinuous by the axial ribs. The columella is short, decidedly twisted, strongly curved and reflected. It is reinforced by the base and provided with a deep-seated fold at its insertion. The parietal wall is glazed with a thin callus.
Distribution
This species occurs in the Pacific Ocean off Terminal Island, California.