Two books from a series that includes Camel, Cheetah, Elephant, Panda, Snake, and Wild Goat. Both Killer Whale and Sea Lion are fact-studded offerings (Did you know that the milk of the California sea lion has 35% fat and 13% protein or that killer whales live in groups called resident pods and transient pods?). But both books suffer from an overall lack of organization that may be baffling to readers. Information is presented in a seemingly random fashion, without the benefits of chapter or subject headings, either of which would have done much to unify the excellent material presented here. An index at the back of each book is only of slight help in this regard. The photographs -- full-color, ample, and lush -- are what distinguish these volumes. Shots of the killer whale's blow hole, both in its open and closed states; close-ups of its teeth; images of baby sea lions nursing at their mothers' sides or rubbing noses are sure to inspire readers and engage them in the marvelous otherness of these fascinating creatures. Indexes.