This book is a marvel of compactness, featuring concise, detailed text on the Identification, Size, Range, Reproduction, and Biology of the nearly 170 elasmobranch species covered, most of which are illustrated with at least one gorgeous, full-color photo and the remainder with a good black-and-white drawing.  Perhaps the best part of the book, however, is the author's  introductory material, surveying elasmobranch Food Habits, Interspecific Interactions, Reproductive Behavior, Development of the Young, Eggcase Types, Social Behavior, Segregation, Social Units, and Diver-Shark Interaction.  A fine list of References provides a helpful guidepost to much important primary literature on many of the species covered.  Also includes an Appendix on courtship and mating in four species of elasmobranch, illustrated with the author's full-color photos.  There is an Index, but its not as detailed as I'd like.  Overall, this is a very compact, useful field guide and reference.