2004) and in the chapters devoted to each class (see Chapters 5\u201315 ). 1.6 Guide to Remaining Chapters This book takes its basic form from the 3rd edi- tion of \u201cThe Ciliated Protozoa\u201d by Corliss (1979). Following this Introduction, we have revised Chapter 2, but used Corliss as the solid grounding for the glossary of terms. Whenever appropriate, cross-reference has been made to terms, and the plural of non-English words has been included. Figures are explicitly referred to by number so that it should be easy to find illustrative support for many of the definitions. Chapter 3 provides a discussion of the approach to constructing our macrosystem. The important charac- ters used to establish different ranks in the hierarchy are described and justification is provided for their use. Some of this is a repetition of the material in this chapter, but in a different context. Chapters 4 through 15 are structured along the lines of the Traité de Zoologie edited by de Puytorac (1994a). The phylum (Chapter 4) and each class (Chapters 5\u201315) are treated under the following topics: overview of the group; taxonomic structure of the group and its diversity; life history and ecology, including symbioses; somatic struc- tures, cortical and cytoplasmic; oral structures; division and morphogenesis; sexuality and life cycle, including nuclear features; and other, a final section that may include aspects of the applied relevance of a group. Chapter 16, a preamble to Chapter 17, deals particularly with important research papers on the genetic diversity of the phylum, especially as these results impact on refining the relationships of taxa. There is also some discussion of character evolu- tion within the phylum, particularly as it relates to the classes and subphyla, and as revealed by the topologies of gene trees. Chapter 17 is the taxonomic chapter, again relying heavily on Corliss (1979) for the basic characterization of groups from the family level and higher. As in Corliss, genera are assigned to families, but there is rarely any discussion of these assignments. Valid genera primarily follow the rec- ommendations of Aescht (2001), whose important work should be referred to for the detailed nomen- clatural background to problematic names. While not considered valid by the International Code of Zoological Nomenclature, nomina nuda have been included and are clearly indicated as such. The References section includes an extensive literature cited section. In this, we have been con- scious of including reference to the classic litera- ture as both Corliss (1961) and Corliss (1979) are now out of print. However, we have also included, as appropriate, citation to important works bearing on the topics of Chapters 4 through Chapters 16. We do regret that we have often been unable to include all relevant literature on a topic, and trust that expert readers will understand and agree with our selection of references.