PreS-Gr 3 This simple introduction teaches scientific classification by highlighting the physical differences among true seals, eared seals, and walruses: flippers, ears, markings, size, tusks, whiskers, and others. Containing less information than other entries in the series (for example, those on sea shells and on spiders), but with a similar format, this sparse text poses questions and encourages readers to look closely at the accompanying black-and-white illustrations. However, although directed towards younger readers, the text fails to includes some basic information, such as how walruses are related to seals and why they are included in the book. The one page on walruses states only that they are not seals and points out the physical differences. Also confusing is the relationship of eared seals to sea lions. The title refers to sea lions, but the text is divided into sections on true seals, eared seals, and walruses. The authors address the question in one line: ``Many eared seals are called Sea Lions.'' A map at the back shows where ``seals, sea lions and walruses'' can be found. This switch in terminology is inexplicable. Except for the map, coverage is confined to the animals' physical characteristics, without facts on habitat, food, life cycle, etc. The narrow focus and the points of confusion limit the appeal and usefulness of this title. Kathleen Odean, formerly at San Rafael Public Library, Calif.