A glossy, attractive title in the ""Sierra Club Wildlife Series,"" focusing on sea lions; true, eared, and fur seals; and walruses. Anatomy, diet, life cycle, location, and endangered status are presented, along with dozens of charming color photos. Odd facts abound: the undercoat of a fur seal contains hairs so fine that 300,000 crowd each square inch; the lenses inside a seal's eyes are spherical, so they can focus a wide range of underwater light rays. Helpful drawings and charts include a double-spread world map, with the locations of common species and full-page drawings that explore questions like: ""How does a seal stay warm?""; ""What do seals eat?""; ""Who are the seals' ancestors?"" While the text is overlong for younger readers, the many inviting photos and extensive index make this accessible to both browsers and students doing assignments.