M.  P Duncan, ?A monograph of the British fossil corals. Second series. Part IV, No. 2. Corals from the zone of Ammonites angulatus (continued). Corals from the zone of Ammonites bucklandi (bisulcatus), Ammonites obtusus, Sow., and Ammonites raricostatus, Ziet?, Monograph of the Palaeontographical Society, vol. 21, pp. 45?73, pl. 12?17, 1868.