Laevapex

Laevapex is a genus of small, freshwater, air-breathing limpets, aquatic pulmonate gastropod molluscs in the family Planorbidae, the ram's horn snails and their allies.^[2]

Laevapex
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Superorder:	Hygrophila
Family:	Planorbidae
Tribe:	Ancylini
Genus:	Laevapex Walker 1903[1]
Type species
Ancylus fuscus C. B. Adams, 1841
Species
See text

Geographic distribution

The genus has a New World distribution. It is widespread throughout the eastern United States, occurring in lakes and slow-flowing rivers.^[3]

Anatomy

These animals have a pallial lung, as do all pulmonate snails, but they also have a false gill or "pseudobranch" which can serve perfectly well as a gill when they are unable to reach the surface for air.^[3]

Members of this genus are characterised by their smooth apex.^[3]

Species

Species within the genus Laevapex include:^[1][2][4]

• Laevapex diaphanus Haldeman, 1841
• Laevapex fuscus C. B. Adams, 1841
• Laevapex peninsulae Pilsbry, 1903
• Laevapex vazi Santos, 1989

Walther (2008) considers North American Laevapex monotypic, collectively synonymising L. diaphanus, L. peninsulae and unidentified Laevapex sp. with L. fuscus, the type species.^[3]