Bryozoans are modular, or colonial, organisms;
each individual colony being built of a few (two or three) to
many (perhaps a million or more) functionally independent units
termed zooids. Colonies may form encrusting sheets, nodules or
erect, branching tree forms; most are calcified to a degree, and
may be bushy and flexible, or rigid, while uncalcified taxa may be
rubbery or gelatinous, or lax and shrubby.