SUMMARYThe dentitions of representatives of the principal families of Insectivora are described and their functions and the types of lateral jaw movement present are deduced from a study of the wear patterns on the crowns of the teeth. The Tenrecoida are compared with the Talpidae and Soricidae, and it is concluded that whereas the latter families have teeth which are capable of both cutting and grinding actions, the Tenrecoidea are specialized for a pure cutting action. The Erinaceidae and Macroscelididae are specialized for a grinding action, with some variation in the latter family, while the Tupaiidae are again generalized.Consideration is given to the differing types of horizontal jaw movement encountered.