The term layers of the subiculum refers to three cyto- and myeloarchitecturally defined substructures of the subiculum. Beginning at the outer limit of the subiculum, i.e., at its boundary with the hippocampal fissure, they are: the molecular layer of the subiculum (layer I), the pyramidal layer of the subiculum (layer 2) and the polymorphic layer of the subiculum (layer 3) ( Bakst-1984 ).