Allen is one of three people who prepared the first edition of Shadows in the Sea in 1963. That work is sometimes considered the "classic" work on sharks. It certainly led the way for other works that include a similar range of information, e.g., Rodney Steel's Sharks of the World (LJ 3/1/86), Facts on File's Sharks (LJ 10/1/87), or Richard Ellis's Book of Sharks (1976). Allen, a former writer for National Geographic, has done well in adding updated information, especially in the areas on shark attacks and uses of sharks; however, he has made far fewer updates to the section on the scientific families, except for the addition of Megachasmidae (Megamouth). He does include rays and skates, which are not covered in the other books, as well as shark legends. Fairly easy reading for the scope of coverage, this book is recommended for secondary schools as well as public and academic libraries.