Phylum Bryozoa - Encrustation coloney

The bryozoa are small, colonial animals whose colonies have two growth forms. One form closely resembles a hydroid colony, and the other form appears as thin encrustation covering the surface of a shell or rock. The latter form is more easily recognized and is common on shells inhabited by hermit crabs. The individuals within a colony may be modified for feeding, reproduction or protection. Each feeding individual is equipped with a crown of tentacles which sweeps food out of the passing water and toward the mouth.