Odostomia desimana
Encyclopedia
Odostomia desimana is a species
of sea snail
, a marine
gastropod mollusk in the family
Pyramidellidae
, the pyrams and their allies.
of the protoconch
are small,
obliquely almost completely immersed in the first of the succeeding whorls, only the periphery of the last two being visible. The nine whorls of the teleoconch are rather high between the sutures, very slightly rounded, slightly angulated at the periphery and scarcely at all shouldered. They are marked by scarcely perceptible lines of growth, and here and there by a faint trace of some very fine microscopic spiral lines. The summit of succeeding whorls falls somewhat anterior to the periphery of the preceding turns, which gives a slightly constricted appearance at the well-impressed suture. The periphery of the body whorl
is faintly angulated. The base of the shell is large, well rounded, narrowly umbilicated and somewhat effuse at the junction of the lip
and columella. The posterior angle is acute. The outer lip is thin. The long columella is slender, almost straight, somewhat revolute, bearing a strong oblique fold near its insertion. The parietal wall is covered by a thin callus.
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 milk-white shell has a regularly elongate-conic shape. It measures 6.7 mm. The whorlsWhorl (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...
of the protoconch
Protoconch
A protoconch is an embryonic or larval shell of some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod...
are small,
obliquely almost completely immersed in the first of the succeeding whorls, only the periphery of the last two being visible. The nine whorls of the teleoconch are rather high between the sutures, very slightly rounded, slightly angulated at the periphery and scarcely at all shouldered. They are marked by scarcely perceptible lines of growth, and here and there by a faint trace of some very fine microscopic spiral lines. The summit of succeeding whorls falls somewhat anterior to the periphery of the preceding turns, which gives a slightly constricted appearance at the well-impressed suture. 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 faintly angulated. The base of the shell is large, well rounded, narrowly umbilicated and somewhat effuse at the junction of the 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....
and columella. The posterior angle is acute. The outer lip is thin. The long columella is slender, almost straight, somewhat revolute, bearing a strong oblique fold near its insertion. The parietal wall is covered by a thin callus.