''Amnicola dalli'',

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

the peninsula amnicola, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

freshwater snail Freshwater snails are gastropod mollusks which 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 ...

with an operculum, an aquatic

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Amnicolidae Amnicolidae is a family of small freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the superfamily Rissooidea. This family is in the clade Littorinimorpha (according to the taxonomy of the Gastropoda by Bouchet & ...

. The specific epithet is in honor of

W. H. Dall William Healey Dall (August 21, 1845 – March 27, 1927) was an American naturalist, a prominent malacologist, and one of the earliest scientific explorers of interior Alaska. He described many mollusks of the Pacific Northwest of America, and w ...

Subspecies

* '' Amnicola dalli johnsoni'' (Pilsbry, 1899) North Peninsula Amnicola
image

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 ** Thin-shell structure Science Biology * Seashell, a hard o ...

is narrowly umbilicate, obtusely conical, shining, slightly striated and brown or greenish horn in color. The shell has 4 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). Whorls in nature File:Photograph and axial plane floral ...

that are gradually increasing in size. Suture is regularly impressed, somewhat deep. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

is rounded before, somewhat angular behind and bluish white within. The lip is simple, sharp, margins joined by a thick callus. The

columella Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire. His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the wo ...

is rather reflexed. The width of the shell is 2.30 mm. The height of the shell is 3.50 mm. File:Amnicola dalli shell 2.jpg, Drawing of the apical view of the shell. File:Amnicola dalli shell 3.jpg, Drawing of the lateral view of the shell.

Anatomy

The jaw is thin and membranaceous. The formula off the radula is: 34-23-7- -7-23-34.

Distribution

The type locality is mountain streams which are tributary to Pyramid Lake in northwestern

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

References

This article incorporates public domain text from reference. Call R. E. 1886. ''On certain recent, quaternary, and new fresh-water Mollusca''
Proceeding Davenport Academy of Natural Sciences, volume V.
pag
2
4
plate I
figure 6. (Radula description and images of radula are by

Charles Emerson Beecher Charles Emerson Beecher (October 9, 1856 – February 14, 1904) was an American paleontologist most famous for the thorough excavation, preparation and study of trilobite ventral anatomy from specimens collected at Beecher's Trilobite Bed. B ...

.) {{DEFAULTSORT:Amnicola Dalli Amnicola Gastropods described in 1884