Odostomia farma
Encyclopedia
Odostomia farma is a species
of sea snail
, a marine
gastropod mollusk in the family
Pyramidellidae
, the pyrams and their allies.
number at least two, and are marked with three slender, spiral lirations, the apex being deeply obliquely immersed in the first of the succeeding turns. The junction of the nucleus and the post-nuclear whorls is marked by a varix
. The five post-nuclear whorls are well rounded. They are marked by three equal and subequally spaced spiral grooves which are crossed by slender axial riblets, the combination of grooves and ribs giving the whorls a pitted appearance. The four raised spaces bounded by the spiral grooves are finely spirally striated. The sutures are deeply channeled. The periphery of the body whorl
is marked by a spiral groove. The base of the body whorl is well rounded. It is marked by four incised lines on the posterior two-thirds, which are equally spaced but grow successively weaker. The peripheral and first subperipheral channel are equal to those on the spire
. All are rendered pitted by the slender axial riblets. The anterior third is smooth. The aperture
is broadly oval, somewhat effuse anteriorly. The posterior angle is acute. The outer lip
is thin. The columella is slender, curved, somewhat reflected and re-enforced by the base. The parietal wall 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 shell is elongate, ovate, and cream-colored. It measures 2.4 mm. The nuclear 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...
number at least two, and are marked with three slender, spiral lirations, the apex being deeply obliquely immersed in the first of the succeeding turns. The junction of the nucleus and the post-nuclear whorls is marked by a varix
Varix (mollusc)
A varix is an anatomical feature of the shell of certain sea snails, marine gastropod molluscs.It is a thickened axial ridge in the shell of some families of gastropods. A varix is located at intervals around the whorl, and is formed by considerable thickening of the outer lip at a resting stage...
. The five post-nuclear whorls are well rounded. They are marked by three equal and subequally spaced spiral grooves which are crossed by slender axial riblets, the combination of grooves and ribs giving the whorls a pitted appearance. The four raised spaces bounded by the spiral grooves are finely spirally striated. The sutures are deeply channeled. 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 marked by a spiral groove. The base of the body whorl is well rounded. It is marked by four incised lines on the posterior two-thirds, which are equally spaced but grow successively weaker. The peripheral and first subperipheral channel are equal to those on the spire
Spire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...
. All are rendered pitted by the slender axial riblets. The anterior third is smooth. 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 broadly oval, somewhat effuse anteriorly. The posterior angle is 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 columella is slender, curved, somewhat reflected and re-enforced by the base. The parietal wall covered by a thin callus.