The only complete guide to all aqautic mammals, dealing with 135 species in all. An introductory and basic reference, each species has a single page account, plus a facing page illustration. The text covers natural history, size, length and weight, distribution, diet, and current status. In seven sections: (1) whales, dolphins, porpoises and river dolphins; (2) seals, sealions, and walruses; (3) sea cows; (4) carnivores; (5) rodents; (6) insectivores, marsupials and monotremes; (7) the great herbivores.