Design and layout of the book

In the following chapters, a brief statement of the morphological features and biology is given for each group or phylum together with an outline classification in which those classes, sub-classes, orders, etc. featured in the text are shown in bold type. Diagnostic features, a drawing (or photograph) and biological notes are given for each species. In some cases it has been possible to make general statements concerning the biology, but in others the specific locality to which the data relates has been given. A scale is not included on the drawings but the size of each species is given in the diagnostic features. Readers who are unable to assign an organism to its correct phylum or group are referred to the illustrated guide on page 10. If the phylum or group to which the organism belongs is known, reference can be made directly to the appropriate chapter. Where identification to species is difficult and beyond the scope of this book, identification has been made to genus. Morphological features are the basis on which identification is made, but it is stressed that in many cases the type of substratum on which the organism is found, position on the shore and distribution are important characteristics. This book has not been designed as an identification key, a selection of such texts is given at the end of each section.