Part of the "Branches on the Tree of Life" series. Phylum Mollusca is the second most diverse phylum of animals, with over 100,000 known species. First examined are the basic characteristics of the phylum-a soft body, muscular foot, mantle cavity with gill, and hard calcified shell. Studies the four most familiar classes of molluscs (chitons, gastropods, bivalves, and cephalopods) in depth, viewing structure, life history, adaptations, and ecological interactions. Accessibility options on the DVD are: (1) expanded description, (2) English subtitles in a black box, (3) subtitled description.