Odostomia dicella
Encyclopedia
Odostomia dicella is a species
of sea snail
, a marine
gastropod mollusk in the family
Pyramidellidae
, the pyrams and their allies.
s are small, very obliquely immersed in the first of the succeeding turns. The five post-nuclear whorls are well rounded. They are marked by four spiral cords between the sutures, the three posterior of which are nodulose on the early whorls. The fourth, or suprasutural one being smooth. On the last whorl the nodules are obsolete. Of these cords, the one at the summit is the weakest and the second below it the strongest. The spaces between the spiral keels are about half as wide as the keels and rather shallow. In addition to the spiral sculpture
the whorls are marked by slender, almost axial riblets, which render the three posterior keels on the early whorls nodulose at their intersections. Of these riblets, about 18 occur upon the second and 22 upon the third whorl. On the fourth, which is the penultimate, the grooves between the keels are crossed by slender axial threads. The sutures are strongly constricted. The periphery of the body whorl
is marked by a narrow, deep sulcus. The base of the shell is moderately long, well rounded. It is marked by five spiral cords which grow successively weaker between the periphery and the umbilical area. The grooves between the sutural cords are equal, crossed by numerous, slender, axial threads, which cause the spaces between the threads and cords to appear as minute pits. The aperture
is moderately large, somewhat effuse anteriorly;.The posterior angle is acute. The outer lip
is thin, showing the external sculpture
within. The inner lip is moderately long, strong, somewhat curved, and reflected over and adnate to the base. It is provided with a slender fold at its insertion. The parietal wall is covered with 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 small shell measures 3 mm. It is elongate-ovate, somewhat translucent, bluish-white. The nuclear whorlWhorl
A whorl is a type of spiral or circular pattern.Other meanings of whorl include:* Whorl , used to describe the attachment of sepals, petals, leaves, or branches at a single point...
s are small, very obliquely immersed in the first of the succeeding turns. The five post-nuclear whorls are well rounded. They are marked by four spiral cords between the sutures, the three posterior of which are nodulose on the early whorls. The fourth, or suprasutural one being smooth. On the last whorl the nodules are obsolete. Of these cords, the one at the summit is the weakest and the second below it the strongest. The spaces between the spiral keels are about half as wide as the keels and rather shallow. In addition to the spiral sculpture
Sculpture (mollusc)
The sculpture of a mollusc shell is the three-dimensional ornamentation on the outer surface, as distinct from the basic shape of the shell itself or colouration. Sculpture may be concave as well as convex. Sometimes it has microscopic detail. Sculpture refers to the calcareous outer layer, not the...
the whorls are marked by slender, almost axial riblets, which render the three posterior keels on the early whorls nodulose at their intersections. Of these riblets, about 18 occur upon the second and 22 upon the third whorl. On the fourth, which is the penultimate, the grooves between the keels are crossed by slender axial threads. The sutures are strongly constricted. 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 narrow, deep sulcus. The base of the shell is moderately long, well rounded. It is marked by five spiral cords which grow successively weaker between the periphery and the umbilical area. The grooves between the sutural cords are equal, crossed by numerous, slender, axial threads, which cause the spaces between the threads and cords to appear as minute pits. 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 moderately large, 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, showing the external sculpture
Sculpture (mollusc)
The sculpture of a mollusc shell is the three-dimensional ornamentation on the outer surface, as distinct from the basic shape of the shell itself or colouration. Sculpture may be concave as well as convex. Sometimes it has microscopic detail. Sculpture refers to the calcareous outer layer, not the...
within. The inner lip is moderately long, strong, somewhat curved, and reflected over and adnate to the base. It is provided with a slender fold at its insertion. The parietal wall is covered with a thin callus.