''Odostomia oldroydi'' is a species of

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

in the family Pyramidellidae, the pyrams and their allies. The epithet "oldroydi" refers to

Ida Shepard Oldroyd Ida Shepard Oldroyd (1856–1940) was an American conchologist and Curator of Geology at Stanford University for over 20 years, who curated what was for a time the second largest collection of mollusk shells in the world. Oldroyd and her husband ...

("Mrs. T.S. Oldroyd").

Description

The elongate-ovate shell is vitreous. Its length measures 3.5 mm. The

whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral d ...

of the

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...

are small, obliquely immersed in the first of the succeeding turns, above which projects the tilted edge which is marked with five raised spiral lirations. The five whorls of the teleoconch are somewhat inflated, well rounded, moderately contracted at the sutures, strongly slopingly shouldered at the summit. They are ornamented with somewhat retractive axial ribs, of which 14 occur upon the first, 16 upon the second, 18 upon the third, and 20 upon the penultimate turn. In addition to the axial ribs, the whorls are marked by four spiral cords between the sutures which are as strong as the ribs and render them strongly nodulous at their junction. The second of these ribs below the summit marks the angle of the shoulder. The spaces enclosed by the ribs and cords are strongly impressed oblong pits, the long axis of which coincides with the spiral sculpture. The sutures are strongly constricted. The periphery of the

body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

is marked by a spiral groove, crossed by the continuations of the axial ribs, which terminate at the posterior edge of the first basal keel. The base of the shell is well rounded posteriorly, somewhat attenuated anteriorly. It is marked by six almost equal spiral keels, which are less developed about the

umbilical Umbilical may refer to: *Umbilical cable *Umbilical cord *Umbilical fold *Umbilical hernia *Umbilical notch *Umbilical vessels **Umbilical artery **Umbilical vein *Umbilical zone *The Umbilical Brothers, two Australian comedic performers, David a ...

area. The deep grooves between these keels are crossed by numerous very slender, raised axial threads. The aperture is oval. The posterior angle is obtuse. The outer lip is thin, showing the external sculpture within. The shell is rendered decidedly sinuous by the spiral cords. The columella is moderately strong, decidedly reflected anteriorly. It is provided with a fold at its insertion.

Distribution

This species occurs in the Pacific Ocean off California.

References

{{Taxonbar, from=Q7078216 oldroydi Gastropods described in 1909