This is the second of three volumes planned to cover the marine patellogastropod, vetigastropod and caenogastropod molluscs. The Caenogastropoda are described in this volume, which concentrates on the Order Littorinimorpha, but includes a further seven families presently unassigned to an order.
The keys are based primarily on the characters shown by fully-grown shells (enabling identification of empty shells), but some external body features are included when they offer important aids to identification. Each species account starts with its most useful diagnostic characters, followed by a description of the shell and body. Information on habitat, food, breeding and the general distribution of the species is also provided.