The first edition of Invertebrate Zoology offered undergraduates studying the biology and evolution of invertebrate animals a new approach to the subject. While the text of the second edition has been revised significantly, the original format has been maintained and enhanced. The chapters, written by expert authors, provide contemporary accounts of the functional, physiological, and reproductive biology of the invertebrate phyla. The final chapter of the book reviews modern interpretations of the phylogeny of invertebrates, based on cladistic and molecular evidence. The study of invertebrates has advanced rapidly in recent years, and several major changes are highlighted in this new edition. Separate chapters now reflect the recognition that the former 'aschelminths' include two disparate groups of phyla, a protostome group related to annelids and molluscs, and an ecdysozoan group related to arthropods. All classifications have been updated, and the relationships among the phyla have been further clarified. Generously illustrated throughout, and with an emphasis on readability and clear presentation, this book will be a valuable resource for all students of invertebrate zoology as well as those involved in current advances in the biological sciences.