Odostomia defolinia
Encyclopedia
Odostomia defolinia is a species
of sea snail
, a marine
gastropod mollusk in the family
Pyramidellidae
, the pyrams and their allies.
number one and one-half, and are the greater part immersed in the first of the succeeding turns. The five post-nuclear whorls are flattened. They are marked by four spiral ridges between the sutures and axial ribs, the intersections of which form low squarish tubercles of which about 11 occur upon the second and 18 upon the penultimate whorl. The sutures are poorly impressed. The periphery of the body whorl
is marked by a spiral cord. The base of the shell is attenuated, marked by six equally spaced spiral cords and slender axial threads in the grooves between the cords. The aperture
is oval. The posterior angle is acute. The outer lip
is thin, showing the external sculpture within. The columella is moderately strong, slightly curved, and provided with a strong fold a little below its insertion.
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 conic shell is crystalline, and shining. It measures 3.6 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 one and one-half, and are the greater part immersed in the first of the succeeding turns. The five post-nuclear whorls are flattened. They are marked by four spiral ridges between the sutures and axial ribs, the intersections of which form low squarish tubercles of which about 11 occur upon the second and 18 upon the penultimate whorl. The sutures are poorly impressed. 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 cord. The base of the shell is attenuated, marked by six equally spaced spiral cords and slender axial threads in the grooves between the cords. 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 oval. 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 within. The columella is moderately strong, slightly curved, and provided with a strong fold a little below its insertion.