Gaster (1924, 1927, 1929, 1932, 1937, 1941, 1944) - Inoceramus labiatus (& Rhynchonella cuvieri) Zone
Biostratigraphical correlation: Inferred to equate with the upper M. geslinianum Zone, the N. juddii Zone and the Mytiloides spp. Zone of current usage.
Lithostratigraphical correlation: Inferred to equate with all but the basal part of the Holywell Nodular Chalk Formation and basal New Pit Chalk Formation in southern England.
Age: Latest Cenomanian & Early Turonian