The conodont genus Cordylodus is interpreted here as a septimembrate apparatus containing M, S and P elements. The individual element morphologies are similar to those found in younger Ordovician apparatuses. Septimembrate apparatus structures are identified in three species studied, C. proavus, C. findstromi, and C. angulatus. A partial apparatus structure is recognised for C. caseyi. Elements previously identified as C. intermedius are now assigned as Sb elements of other species of Cordylodus. The Cordylodus intermedius Zone, lying above the Cordylodus proavus Zone and below the Cordylodus angulatus Zone, is here replaced by a lower Hirsutodontus simplex Zone and an upper Clavohamulus hintzei Zone. Both zones were formerly subzones of the Cordylodus intermedius Zone (Miller, 1988) or the upper part of the earlier-used Cordylodus proavus Zone (Miller, 1984). The term makellate is introduced to describe an element shape category that includes most M elements, which have previously been included in the dolabrate group of elements.