| Pyrgulopsis | |
|---|---|
| |
| Apertural view of a shell of † Pyrgulopsis nevadensis . | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Order: | Littorinimorpha |
| Family: | Hydrobiidae |
| Subfamily: | Nymphophilinae |
| Genus: | Pyrgulopsis Call & Pilsbry, 1886 [1] |
| Diversity [2] [3] | |
| 133 species | |
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 , another genus of snail, and opsis = aspect of. [1]
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 edge of the aperture, called the peritreme, is continuous. [1] The operculum is ovate, thin, corneous and spiral, with polar point well forward and approximating the columella. [1]
The jaw is thin and membranaceous. [1] The radula is 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. [1]
The distribution of the genus Pyrgulopsis includes Western and South-western United States. [1] Snails of species in the genus Pyrgulopsis occur in fresh water and in brackish water. [1]
Pyrgulopsis is the largest genus of freshwater gastropods in the North America. In 2014, 139 species were recognized in this genus. [4]
Species in the genus Pyrgulopsis include: [5]
Eastern North American species of Pyrgulopsis [20] are considered to be in separate genus Marstonia according to the Thompson and Hershler (2002). [21]
This article incorporates public domain text from the reference. [1]