Monostroma quaternarium
- kingdom: Plantae
- phylum: Chlorophyta
- class: Ulvophyceae
- order: Ulotrichales
- family: Gomontiaceae
- genus: Monostroma
- species: Monostroma quaternarium
Weymouth
England
United Kingdom
Albany- Ben Lomond
- Berkeley
- Bolinas
- Brookdale
- Santa Cruz
California- Honolulu
Hawaii- Coupeville
Washington
United States