Flustra foliacea; Print; Flustra foliacea is a species of bryozoans found in the northern Atlantic Ocean. It is a colonial animal that is frequently mistaken for a seaweed. Colonies begin as encrusting mats; and only produce loose fronds after their first year of growth. They may reach 20 cm (8 in) long; and smell like lemons. Its microscopic structure was examined by Robert Hooke and illustrated in his 1665 work Micrographia.