Gaster (1924, 1927, 1929, 1932, 1937, 1941, 1944) - Holaster planus Zone
Biostratigraphical correlation: Inferred to equate with an interval from the base to within the top of the S. plana Zone of current usage.
Lithostratigraphical correlation: Inferred to equate with the lower to middle Lewes Nodular Chalk of southern England.
Age: Late Turonian