It is not often you can preview a book before buying. The contents of this very comprehensive field guide can be found in Bernard Picton's website. The book includes a few extra illustrations but essentially the book and the website have the same content. Compared with most guides with colour photos, the photos in the book are large - only two per page - which allows many of the nudibranchs to be photographed on their food - and to still be clearly visible. The book provides key characters for each species, to allow identification in the field, but it is much more than just an identification guide, including a wealth of information on the natural history of each species. As those of you, who visit the Forum often, already know, Bernard Picton has an expert knowledge, not only of the British opisthobranch fauna, but of many other marine groups as well. He is therefore able to bring a depth of background knowledge to this guide, making it essential reading for all those with an interest in the north Atlantic marine fauna, as well as to those with just an interest in opisthobranchs. But the best way to decide whether this book is for you is to have a look at the web version.