Pyrgulopsis
| Pyrgulopsis | |
|---|---|
 |
|
| Apertural view of a shell of †Pyrgulopsis nevadensis. | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| (unranked): |
clade Caenogastropoda clade Hypsogastropoda |
| Superfamily: | Rissooidea |
| Family: | Hydrobiidae |
| Subfamily: | Nymphophilinae |
| Genus: |
Pyrgulopsis Call & Pilsbry, 1886 |
| Diversity | |
| 133 species | |
clade Hypsogastropoda
clade Littorinimorpha
Pyrgulopsis is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae.
The name Pyrgulopsis is composed from Pyrgula and opsis = of.
Generic characters of the genus Pyrgulopsis are: the shell is minute, conically turreted, somewhat elongated, imperforate and unicarinate. The apex is acute. The aperture is ovate. The peritreme is continuous.
The operculum is ovate, thin, corneous and spiral, with polar point well forward and approximating the columella.
The jaw is thin and membranaceous.
The radula is like this: Odontophore with teeth are arranged in transverse rows, according to the formula 3 + 1 + 3. Formula for denticles of rhachidian:
4 + 1 + 4⁄1 + 1.
The distribution of the genus Pyrgulopsis includes Western and South-western United States.
Snails of species in the genus Pyrgulopsis occur in fresh water and in brackish water.
Pyrgulopsis is the largest genus of freshwater gastropods in the North America. In 2010, 133 species were recognized in this genus.
Species in the genus Pyrgulopsis include:
Eastern North American species of Pyrgulopsis are considered to be in separate genus Marstonia according to the Thompson and Hershler (2002).
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