Collarina balzaci is an encrusting bryozoan. Colonies form small irregular patches. The autozooids are small oval and convex, with indistinct boundaries. They range in size from 0.43 – 0.53 by 0.26 -0.41 mm and have three to five spines.
The species is able to colonise a range of substrates, including shells, stones, red algae, Sargassum seaweed and Posidonia seagrass. It is especially found on small pieces of substrate. Little information is available on its depth range in the British Isles. It has been collected at 18-27 metres from the Isle of sky, 46 metres off Plymouth, 82 metres off Wick and as deep as 135 metres off the Faroes
Collarina balzaci is a Mediterranean species, distributed south to Madeira, the Canary Isle and the Azores. It range extends north to the west end of the English Channel, and along the western coast of Britain and Ireland to Faroe, where it probably reaches its northern limit.
This species has a long history of confusion with British Cribrilina species.