Pyrgulopsis deserta | |
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Drawing of apertural view of two shells of Pyrgulopsis deserta. | |
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Species: | P. deserta |
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Pyrgulopsis deserta | |
Synonyms | |
Pyrgulopsis deserta is a species of freshwater snail in the family Hydrobiidae, the mud snails. It is known by the common names desert springsnail, Virgin springsnail, and St. George snail. [2] It occurs in southwestern Utah and northwestern Arizona in the United States. [3]
Pyrgulopsis deserta was originally described as Amnicola deserta by Henry Augustus Pilsbry in 1916. [1]
Pilsbry's original text (the type description) reads as follows:
The shell is very small, perforate, broadly ovate, corneous,
translucent, thin; surface glossy, very minutely marked with delicate growth-lines. The outlines of the spire are convex, the apex somewhat pointed. Whorls 3½, strongly convex, the last more rapidly descending close to the aperture. The aperture is ovate, somewhat oblique, angular above. Peristome continuous and free from the preceding whorl. Length 2.4, diam. 1.7 mm.; longest axis of aperture 1.25 mm. Length 2.2, diam. 1.6 mm.
Washington Co., Utah. Types no. 121,112, Wheatley collection, in coll. A. N. S. P.
This little shell resembles the larger Bythinella palomasensis , from Lake Palomas in northern Chihuahua (NAUTILUS IX, 68, Oct., 1895; Dall, Proc. U. S. Nat. Mus. XIX, 1897, p. 369, pi. 31, fig. 9). The present species is broader, and evidently old individuals are smaller. The generic position is uncertain. As between a short Paludestrina and a long Amnicola there is little choice.
Washington county is in the southwestern angle of Utah, drained by the Virgin river, flowing into the Colorado. The specimens are "dead" shells, but not fossil, I think. According to the label, Oreohelix strigosa was found in the same place. The collector was not given for this or the preceding.
All of the adult specimens of A. deserta have the last whorl shortly free at the aperture. It is a senile form, probably extinct or on the verge of extinction, Amnicolidae lead a precarious existence in the arid states. The rivers do not afford suitable stations. They have apparently never gained access to the small perennial streams of the higher mountains; and permanent springs and streams are so rare on the lower levels that the colonies are small, few and widely separated. The large proportion of extremely diminutive species in the arid region is remarkable. It may, perhaps, be looked upon as a permanent
dwarfing due to unfavorable conditions.
The shoal sprite was a species of minute, air-breathing, freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails. This species was endemic to Alabama, but it is now extinct.
Neoplanorbis tantillus is a species of very small air-breathing freshwater snail, an aquatic gastropod mollusk in the family Planorbidae, the ram's horn snails. This species is endemic to the United States. In 2012, it has been declared extinct by the IUCN Red List of Threatened Species.
Pyrgulopsis is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae.
The Grand Wash springsnail is a species of freshwater snail in the family Hydrobiidae, the mud snails. It is endemic to Mohave County, Arizona, in the United States.
The Kingman springsnail is a species of freshwater snail in the family Hydrobiidae, the mud snails. It is endemic to Mohave County, Arizona, in the United States.
The Gila springsnail, scientific name Pyrgulopsis gilae, is a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Hydrobiidae.
The Page springsnail is a species of freshwater snail in the family Hydrobiidae, the mud snails. It is endemic to Arizona in the United States, where it is known only from the Upper Verde River drainage in Yavapai County.
The corded purg, scientific name Pyrgulopsis nevadensis, is an extinct species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Hydrobiidae.
Microphysula cookei, common name the Vancouver snail, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Thysanophoridae.
The Socorro springsnail, scientific name Pyrgulopsis neomexicana, is an endangered species of minute freshwater snail with a gill and an operculum, an aquatic gastropod mollusk or micromollusk in the family Hydrobiidae, the mud snails.
Holospira mesolia, common name widemouth holospira, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Urocoptidae.
Oreohelix carinifera, common name keeled mountainsnail, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Oreohelicidae.
Amnicola walkeri, common name Canadian duskysnail, is a species of freshwater snail, an aquatic gastropod mollusk in the family Amnicolidae.
Amnicola missouriensis, common name the Missouri amnicola, is a species of freshwater snail, an aquatic gastropod mollusk in the family Amnicolidae.
Marstonia scalariformis, previously known as Pyrgulopsis scalariformis, common name the moss pyrg, is a species of freshwater snail with a gill and an operculum, aquatic gastropod mollusk in the family Hydrobiidae.
Marstonia is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae.
Pyrgophorus spinosus, common name the spiny crownsnail, is a species of very small freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Hydrobiidae.
Marstonia comalensis is a species of minute freshwater snail with a gill and an operculum, an aquatic gastropod mollusk or micromollusk in the family Hydrobiidae. It is found in south central Texas, United States.
Potamolithus rushii is a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Lithoglyphidae.
Pyrgulopsis aardahli, commonly known as the Benton Valley springsnail, is a species of minute freshwater snails with an operculum, aquatic gastropod molluscs or micromolluscs in the family Hydrobiidae.
This article incorporates a public domain text from reference. [1]