The subject matter is profusely illustrated with a number of clear and labelled diagrams. We sincerely feel that this book will fulfill the requirements of the students as well as teachers. While preparing this book several standard reference books and text books have been consulted. Emphasis has been laid on furnishing maximum information required for students in a simple and lucid language. Zoology is an interesting subject because the animal world is full of diversity, adaptations, habits and habitats and behaviour.