Deflandrea rectangularis ssp. rectangularis

Autonym. Now redundant.
Originally Deflandrea rectangularis ssp. rectangularis, subsequently Amphidiadema rectangularis ssp. rectangularis.
Holotype: Cookson and Eisenack, 1962, pl.1, fig.14
Locus typicus: Perth Basin, Australia
Stratum typicum: Late Turonian-Middle Senonian

Original description: Cookson and Eisenack, 1962, p.486
Shell elongate, flat, either nearly rectangular in outline or slightly narrowed above the limits of the capsule. Apex truncate to rounded, sometimes with a low central elevation. Antapex truncate to rounded or with slight indications of horns. Tabulation, girdle and longitudinal furrow absent. Capsule circular to oval in outline, generally reaching the lateral margins of the shell. Wall of shell and capsule smooth, that of the capsule being thinner.
Dimensions: Holotype: 120 Ám long, 60 Ám broad; capsule 40x58 Ám broad; pylome 24x26 Ám. Range: 100-130 Ám long, 56-64 Ám broad.