Griffith & Brydone (1911); Brydone (1912) - abundant O. pilula Subzone
Biostratigraphical correlation: Equates with an interval from within the E. depressula Subzone to just below the top of the Subzone of abundant O. pilula of current usage (Young & Lake, 1988).
Lithostratigraphical correlation: Equates with the upper part of the Newhaven Chalk and, locally, the basal part of the Culver Chalk Formation of southern England.
Age: Campanian