Caulacanthus ustulatus
- kingdom: Plantae
- phylum: Rhodophyta
- class: Florideophyceae
- order: Gigartinales
- family: Caulacanthaceae
- genus: Caulacanthus
- species: Caulacanthus ustulatus
Knokke-Heist
Flanders
BelgiumSooke
British Columbia
CanadaFunchal
MadeiraAreosa
Viana do Castelo
Viana do Castelo
PortugalBroadstairs
Combe Martin
Dover
Eastbourne
Ramsgate
England
United KingdomHonolulu
Hawaii
United States