Odostomia astricta

Odostomia astricta
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
(unranked):	clade Heterobranchia clade Euthyneura clade Panpulmonata
Superfamily:	Pyramidelloidea
Family:	Pyramidellidae
Genus:	Odostomia
Species:	O. astricta
Binomial name
Odostomia astricta Dall & Bartsch, 1907 [1]
Synonyms
Chrysallida astricta Dall & Bartsch, 1907 Odostomia (Chrysallida) astricta Dall & Bartsch, 1907

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

Description

The elongate-conic shell is bluish-white. It measures 2.9 mm. The nuclear whorls are decollated. The seven post-nuclear whorls are very slightly rounded, separated by deeply channeled sutures. In this species the axial ribs exceed the four spiral keels in strength, their junction forming elongated tubercles the long axis of which coincides with the spiral keels. The axial ribs, of which there are 16 upon all of the turns, slant decidedly backward near the aperture. They are rather distantly spaced and the spaces inclosed between them and the spiral keels are deep oblong pits, the long axis of which coincides with the spiral sculpture. The periphery of the body whorl is marked by a deep, wide channel across which the ribs extend feebly to the first subperipheral keel. The base of the shell is rather long and well rounded, marked by seven rather narrow, slender spiral keels which successively decrease in strength from the periphery to the umbilical area, the anterior ones being only faintly indicated. The spaces which separate the keels are about twice as wide as the keels and are crossed by many slender raised axial threads. The aperture is oval. The outer lip is rather thick. The columella is twisted, reenforced by the attenuated base and provided with a moderately strong fold at its insertion. The parietal wall is covered by a strong callus. ^[4]

Distribution

This species occurs in the Pacific Ocean off California.

References

1. ^ Dall and Bartsch, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 515, pi. 46, fig. 1
2. ^ Rosenberg, G. (2011). Odostomia astricta Dall & Bartsch, 1907. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=581101 on 2011-10-26
3. ^ 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.
4. ^ William Healy Dall and Paul Bartsch , "A Monograph of West American Pyramidellid Mollusks" , Smithsonian Institution, 1909

External links

External identifiers for Odostomia astricta
WoRMS	581101

• To World Register of Marine Species