"This work is a specialized dissertation covering a limited field of enquiry. I deal mainly with two interrelated topics, the structure of the male postabdomen and genitalia of cyclorrhaphous flies and how these insects should be classified in a phylogenetic system. Much new information and interpretation is presented here, as well as commentary on the observations and interpretation of previous authors. The field covered by this work has long been recognized as difficult. It is my hope that I will succeed in this work in dispelling some of the difficulties. My proposal of revised terminology for certain parts of the external genitalia thus should not be regarded as innovation for its own sake, but as an attempt to remedy a situation which has been widely recognized as unsatisfactory."--Page 2

This volume provides individual treatments of the major molluscan taxa. Each chapter provides an overview of the evolution, phylogeny and classification of a group of molluscs, as well as more specific and detailed coverage of their biology (reproduction, feeding and digestion, excretion, respiration etc.), their long fossil record and aspects of their natural history. The book is illustrated with hundreds of colour figures. In both volumes, concepts are summarised in colour-coded illustrations. Key selling features: Comprehensively reviews molluscan biology and evolutionary history Includes a description the anatomy and physiology of anatomical systems Up to date treatment with a comprehensive bibliography Reviews the phylogenetic history of the major molluscan lineages

A valuable contribution to the on-going discussions on evolution within the Orchid family. Dressler's work delimits several major natural groups and emphasises areas needing further study.

Well-labelled illustrations, diagrams, tables, figures and experiments have been given to support the text, wherever necessary.

Animal phylogeny is undergoing a major revolution due to the availability of an ever increasing amount of molecular data, the application of novel methods of phylogenetic reconstruction, and advances in palaeontology and molecular developmental biology.This book revises the major events in animal evolution in the light of these recent advances.