1 Environmental Considerations2 Invertebrate Classification and Relationships3 The Protozoans4 The Poriferans and Placozoans5 Introduction to the Hydrostatic Skeleton6 The Cnidarians7 The Ctenophores8 The Platyhelminthes9 The Mesozoans: Possible Flatworm Relatives10 The Nemertines11 The Rotifers and Acanthocephalans12 The Molluscs13 The Annelids and Sipunculans14 The Arthropods15 Two Phyla of Likely Arthropod Relatives: Tardigrada and Onychophora16 The Nematodes17 Four Phyla of Likely Nematode Relatives: Nematomorpha, Priapulida, Kinorhyncha, and Loricifera 18 Five Phyla (Plus One Species) of Uncertain Affiliation: Myxozoa, Gnathostomulida, Gastrotricha, Xenoturbella bocki, Chaetognatha, and Cyliophora19 The Lophophorates (Phoronids, Brachiopods, Bryozoans) and Entoprocts20 The Echinoderms21 The Hemichordates22 The Nonvertebrate Chordates23 Invertebrate Reproduction and Development--An OverviewGlossaryIndex
