Pisidium

Pisidium
External view of the left valve of Pisidium pseudosphaerium
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Sphaeriida
Superfamily: Sphaerioidea
Family: Sphaeriidae
Genus: Pisidium
C. Pfeiffer, 1821
Species

See text

Synonyms

Tetragonocyclas Pirogov & Starobogatov, 1974

Pisidium is a genus of very small or minute freshwater clams known as pill clams or pea clams, aquatic bivalve molluscs in the family Sphaeriidae, the pea clams and fingernail clams.

In some bivalve classification systems, the family Sphaeriidae is referred to as Pisidiidae, and occasionally Pisidium species are grouped in a subfamily known as Pisidiinae.