The papillae basilares of species ofeight families of lizards have been studied by scanning electron microscopy. Two basic types of simpler papillae basilares are found in species of three families, namely the Iguanidae, Agamidae and Anguidae. The papillae in all these families contain both short and long-ciliated hair cells; the region of short-ciliated hair cells may be either central or apical in location. Species of lacertid, teiid and varanid lizards show possibly more advanced papillae made up only of short-ciliated hair cells. Species of gekkonid and scincid lizards have what are probably more advanced types of papillae, each with peculiar modifications. All lizard papillae basilares exhibit simple or complex kinocilial bidirectionality as well as a limited region of kinocilial unidirectionality.