Odostomia cassandra
Encyclopedia
Odostomia cassandra is a species
of sea snail
, a marine
gastropod mollusk in the family
Pyramidellidae
, the pyrams and their allies.
are deeply immersed in the first of the succeeding turns. The four post-nuclear whorls are very strongly, tabulatedly shouldered at the summit, moderately rounded. They are marked by fine incremental Iines, and numerous exceedingly closely spaced, very fine, spiral striations. The sutures are strongly constricted. The periphery of the body whorl
is well-rounded. The base of the shell is rather long, well-rounded. The aperture
is very large and broadly oval. The posterior angle is decidedly obtuse. The outer lip
is very thin. The inner lip is very slender, very oblique, somewhat sinuous, strongly curved, and slightly reflected over the base, but not appressed to it. It is provided with a weak fold some little distance anterior to 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 small shell measures 2.5 mm. It is, ovate, very thin, semitransparent, light yellow. 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 deeply immersed in the first of the succeeding turns. The four post-nuclear whorls are very strongly, tabulatedly shouldered at the summit, moderately rounded. They are marked by fine incremental Iines, and numerous exceedingly closely spaced, very fine, spiral striations. 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 well-rounded. The base of the shell is rather long, well-rounded. 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 very large and broadly oval. The posterior angle is decidedly obtuse. 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 very thin. The inner lip is very slender, very oblique, somewhat sinuous, strongly curved, and slightly reflected over the base, but not appressed to it. It is provided with a weak fold some little distance anterior to its insertion.