Jukes-Browne & Hill (1903, 1904) - Rhynchonella cuvieri Zone
Biostratigraphical correlation: Inferred to equate with the M. geslinianum Zone (pars), N. juddii Zone and Mytiloides spp. Zone of current usage.
Lithostratigraphical correlation: Equates with all but the basal part of the Holywell Nodular Chalk Formation in southern England.
Age: Late Cenomanian & Early Turonian.