This is the first time the lowly barnacle has ever been honored with a full-scale, yet popularly oriented book of its own, so there is a priori value here. Ross and Emerson survey barnacle classification, sex life, physiology and defenses at middling length and then touch briefly on curious forms (some species live on whales and turtles), commercial uses (few, though barnacle cement is of interest to science), Darwin's famous researches, and methods for collectors. The result is an uneven but surprisingly unforbidding blend of technical and casual information, idled out with useful photos and sketches.