Callopora dumerilii is an encrusting bryozoan, found throughout the northern temperate zone. It is common from Norway to Madeira and into the Mediterranean.
Colonies form broad irregular sheets on stones, shells and kelp holdfasts. Callopora dumerilii is essentially a shallow water species ranging from the lower shore into the shallow subtidal water, although its depth limit is unknown. It has previously been reported from 300 m.