Odostomia kelseyi
Encyclopedia
Odostomia kelseyi is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of sea snail
Sea snail
Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....

, a marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 gastropod mollusk in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Pyramidellidae
Pyramidellidae
Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs or micromolluscs....

, the pyrams and their allies.

Description

The small, ovatel shell measures 2.7 mm. It is bluish-white. The nuclear whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

 are small, obliquely immersed in the first of the succeeding turns, above which only the tilted edge of the last volution projects. The six post-nuclear whorls are moderately rounded and narrowly shouldered at the summit. They are marked only by moderately retractive lines of growth and numerous exceedingly fine, spiral striations. The sutures are subchanneled. The periphery of the body whorl
Body whorl
Body whorl is part of the morphology of a coiled gastropod mollusk.- In gastropods :In gastropods, the body whorl, or last whorl, is the most recently-formed and largest whorl of a spiral or helical shell, terminating in the aperture...

 is somewhat inflated and well rounded. The base of the shell is moderately long, sloping evenly from the periphery to the anterior extremity. The area about the umbilicus has a pinched-in effect. The base is surrounded by a somewhat tumid area. The aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

 is large, broadly oval, somewhat flaring at the anterior lateral angle. The posterior angle acute. The outer lip
Lip (gastropod)
In the shell of a gastropod mollusk , the margin of the aperture is called the lip or the peristome. In other words, this is a term used to describe part of gastropod shell anatomy....

 is thin. The inner lip decidedly curved and slightly revolute. The parietal wall is covered with a thick calls which joins the callus of the columella to the posterior angle of the aperture, rendering the margin of the aperture complete. No fold is visible on the columella. The thin operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

is horny, pauci-spiral, concavo-convex, the convex side being the outer.

External links

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