Fig. 11.—Sketch map from air photographs of the Mangaotane Valley section, the type locality for the Teratan, Mangaotanean, and Arowhanan stages. Column shows lithology and approximate thickness of stages. Inoceramus nukeus was found in a boulder in Te Rata Stream about 300ft below the base of the Piripauan. (Seitz, 1956). The ammonites and other molluscs from Amuri Bluff were described by Woods (1917) as being upper Senonian (probably Campanian and Maestrichtian in terms of the divisions used in this paper). The ammonites need re-examination in the light of the new stratigraphic information. The Teratan contains two related key species in sequence, Inoceramus nukeus occurring regularly above I. opetius I. opetius resembles I. lingua Goldfuss, a form shown by Seitz (1956) to range from upper Santonian to lower Campanian. I. nukeus resembles I. lobatus Goldfuss, which according to Woods (1912) ranges