||Assemblages on hard or mixed substrates that are dominated by either attached, stalked
crinoids (or "sea lilies") or motile (but often stationary, see Barnes 1980), comatulid
(or "feather stars"). These animals are common in the deep sea and in other areas.
Crinoids are a Class of echinoderm characterized (in general) by a stalk that supports
the body, mouth, and arms of the animal. The branching arms are equipped with ciliated
grooves that carry food items to the central, upward-facing mouth.