ABSTRACTPart 4 of the monograph on the articulate brachiopods from the Wenlock Series (Silurian) of the Welsh Borderland and South Wales completes the description of the members of the superfamily Strophomenacea, together with those of the Chonetacea and some of the Pentameracea. 34 species and subspecies (7 under open nomenclature) are assigned to 18 genera and subgenera, and their geographical and stratigraphical distributions are outlined. One genus (Scamnomena) and 4 species are new.