The encrusting sponges grows to about 1 cm thick. It is a thinly encrusting sponge which is highly variable in both shape and colour. It may be encrusting with small turrets or form branching structures with tall turrets
These sponges lives from the subtidal zone and down to at least 15m underwater. It may encrust mussels or other hard surfaces or be found under stones in sheltered to moderately exposed areas.