What's the difference between i.e. and e.g.?
any member of the order Zoanthidea, a group of about 300 species of marine animals of the class Anthozoa (phylum Cnidaria) characterized by a polyp (i.e., a cylindrical stalklike structure with a mouth and tentacles at the upper end and attached to a surface at the lower end). The zoanthid closely resembles the sea anemone, differing from it chiefly in being generally smaller and in having a mucous coat to which sand and other materials adhere.