Odostomia callipyrga
Encyclopedia
Odostomia callipyrga is a species
of sea snail
, a marine
gastropod mollusk in the family
Pyramidellidae
, the pyrams and their allies.
are well rounded, marked by four spiral cords, similar to those on the spire, the space between which is ornamented like the grooves in
the spire
. The aperture
is oval. The posterior angle is acute. The outer lip
is thin, showing the external sculpture within. The columella is slender, somewhat curved and slightly reflected, provided with a fold at 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 white, oblong-ovate shell is somewhat ventricose. It measures 2.2 mm. The nuclear horl (mollusc)|whorls]$ are nearly half immersed in the first of the succeeding turns. The four post-nuclear whorls are somewhat inflated, moderately contracted at the periphery and moderately shouldered at the summit. They are marked by strong spiral cords of which 2 appear upon the first, 3 upon the second, and 4 upon the penultimate turn between the sutures. These cords are separated by well impressed, narrow, spiral grooves which are crossed by slender axial threads. The periphery and the base of the body whorlBody 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...
are well rounded, marked by four spiral cords, similar to those on the spire, the space between which is ornamented like the grooves in
the spire
Spire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...
. 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 slender, somewhat curved and slightly reflected, provided with a fold at its insertion.