Since H.A. Pilsbry's classic work on the chitons (Polyplacophora), published between 1892 and 1894 in the Manual of Conchology, there has been no comprehensive taxonomic review of this group. Piet Kaas and Richard van Belle changed this when they started the book series Monograph of Living Chitons, which aimed, after a careful study of the type material, to systematically describe and illustrate every known - or hitherto unknown - species. The first five volumes were published between 1985 and 1994. The sudden death of seniour author Piet Kaas in 1996 postponed the publication of Volume 6. The unfinished manuscript was taken up by a new author, Hermann Strack, who in collaboration with van Belle managed to finish it. In Volume 6 no less than 167 species are treated and depicted, of which 3 are described as new. Two important families are covered: the Schizochitonidae and the Chitonidae. Especially the coverage of the Chitonidae, with well know and species-rich genera and subgenera as Chiton, Rhyssoplax, Acanthopleura, Tonicia, Lucilina and Onithochiton is long awaited and will prove very useful to researchers, students and collectors alike.