Griffith & Brydone (1911); Brydone (1912) - Zone of Plocoscyphia labrosa and Stauronema carteri
Biostratigraphical correlation: Inferred to equate with all or part of the N. carcitanense Zone of current usage.
Lithostratigraphical correlation: Equates with the basal part of the West Melbury Marly Chalk Formation in southern England.
Age: Earliest Cenomanian.