''Fontigens aldrichi'', common name the Missouri amnicola, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

freshwater snail Freshwater snails are gastropod mollusks that live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs t ...

, an

aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Fontigentidae Fontigentidae is a family (biology), family of small freshwater snails with a gill and an operculum (gastropod), operculum, Aquatic animal, aquatic gastropod mollusks in the superfamily Truncatelloidea. MolluscaBase eds. (2025). MolluscaBase. Fon ...

Shell description

The

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

is minute, imperforate, obliquely ovate, light brown. The surface of the shell is smooth except for slight growth-lines. The shell is composed of 3½ very convex

whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagram ...

separated by unusually deep sutures. The

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics) A-Bomb Abomination Absorbing Man Abraxas Abyss Abyss is the name of two characters appearing in Ameri ...

is obtuse and often eroded. The

last whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

is shortly deflexed in front in adult specimens. The

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

is rotund-ovate, being slightly narrowed above, but not angular there. The aperture is not modified in form by the preceding whorl. The aperture is moderately oblique. The peristome is continuous, not closely appressed at the upper left side. The columellar margin is thick and calloused within. The width of the shell is 1.3 mm. The height of the shell is 1.7 mm. The height of aperture is 0.8 mm. The shell of ''Fontigens aldrichi'' is much smaller than '' Bythinella aldrichi'' Call, shorter, with a thick and heavy columellar lip.

Distribution

Type locality is

Carter County, Missouri Carter County is a county in the Ozarks of Missouri. At the 2020 census, it had a population of 5,202. The largest city and county seat is Van Buren. The county was officially organized on March 10, 1859, and is named after Zimri A. Carter, a ...

References

This article incorporates public domain text from reference. * *

External links

* * * {{Taxonbar, from2=Q3140787, from1=Q4930948 aldrichi Gastropods described in 1886