Cryptosula pallasiana is an encrusting bryozoan, common to British shores and shallow subtidal waters. The colonies form white, pink or orange sheets, several centimetres in diameter. Deep brown opercula (flap-like folds of the body wall which close the orifice) are clearly visible across the colony surface.
C. pallasiana colonises a range of algal and hard substrata. The species is distributed from Norway to the Mediterranean and Black Sea and on the Atlantic coast of Canada and the USA to Florida. C. pallasiana frequently fouls boat hulls and has been reported from docks and harbours in New Zealand.