Odostomia angularis
Encyclopedia
Odostomia angularis is a species
of sea snail
, a marine
gastropod mollusk in the family
Pyramidellidae
, the pyrams and their allies.
are small, deeply obliquely immersed in the first of the succeeding turns, above which the tilted edge of the last turn only is visible. The seven post-nuclear whorls are slightly rounded, and separated by constricted sutures. They are marked by numerous slender, wavy subequal and subequally closely spaced spiral striations, of which about 33 occur upon the last turn between the summit and the periphery. The periphery of the body whorl
is marked by a slender raised keel, decidedly angulated. The base of the shell is short, moderately rounded. It is narrowly attenuated anteriorly to reinforce the columella, sculptured like the posterior portion of the whorls. The ovate aperture
is very broad and slightly effuse anteriorly. The posterior angle is acute. The columella is very slender, evenly curved, closely appressed to the attenuated base, with a strong fold at its insertion, which is barely visible when the aperture is viewed squarely.
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 very regularly elongate-conic shell is subdiaphanous to milk-white. It measures 5.6 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...
are small, deeply obliquely immersed in the first of the succeeding turns, above which the tilted edge of the last turn only is visible. The seven post-nuclear whorls are slightly rounded, and separated by constricted sutures. They are marked by numerous slender, wavy subequal and subequally closely spaced spiral striations, of which about 33 occur upon the last turn between the summit and the periphery. 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 slender raised keel, decidedly angulated. The base of the shell is short, moderately rounded. It is narrowly attenuated anteriorly to reinforce the columella, sculptured like the posterior portion of the whorls. The ovate 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 very broad and slightly effuse anteriorly. The posterior angle is acute. The columella is very slender, evenly curved, closely appressed to the attenuated base, with a strong fold at its insertion, which is barely visible when the aperture is viewed squarely.