| Aspect: | Thin blue encrusting hard rubbery cushion with star-shaped network of veinous canals radiating from the excurrent openings. The "stars" are not connected. |
| Population: | Common. |
| Notable feature: | Generally blue as the caerulea (sky colour) in the latin scientific designation implies and ommited in the English designation, but pink variations not rare. |
| Environment: | Relatively flat surfaces, wreck hulls included, down to at least 25 metres. |
| Behaviour: | - |
