Odostomia armata
Encyclopedia
Odostomia armata is a species
of sea snail
, a marine
gastropod mollusk in the family
Pyramidellidae
, the pyrams and their allies.
are deeply, obliquely immersed in the first of the succeeding turns. The six post-nuclear whorls are marked by two strongly elevated tuberculate keels between the sutures, the posterior one of which is about twice as wide as its neighbor. Of the crenulations about 20 appear upon the second and third, 22 upon the fourth, and 24 upon the penultimate turn.
The sutures are strongly channeled. The periphery is marked by a slender keel, while the base has two a little weaker than the peripheral one which divides the space between this and the umbilical area into three equal parts. The aperture
is ovate. The outer lip
is thin. The columella is rather thick, reflected and provided with a slender fold at its insertion. The parietal wall is provided 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 elongate-conic shell is white. It measures 2.5 mm. The two 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...
are deeply, obliquely immersed in the first of the succeeding turns. The six post-nuclear whorls are marked by two strongly elevated tuberculate keels between the sutures, the posterior one of which is about twice as wide as its neighbor. Of the crenulations about 20 appear upon the second and third, 22 upon the fourth, and 24 upon the penultimate turn.
The sutures are strongly channeled. The periphery is marked by a slender keel, while the base has two a little weaker than the peripheral one which divides the space between this and the umbilical area into three equal parts. 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 ovate. 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 rather thick, reflected and provided with a slender fold at its insertion. The parietal wall is provided with a thin callus.