The term area 6a beta of Vogts refers to a cytoarchitecturally defined subdivision of area 6 of Brodmann (guenon). It and area 6a alpha of Vogts constitute area 6a of Vogts. The alpha subarea is more caudal; the beta subarea more rostral. Areas 6a alpha and beta differ in that in area 6a beta the molecular layer (I) and the zone extending from the third sublayer of the external pyramidal layer (III) through the internal pyramidal layer (V) are narrower, and the differentiation of layer V into a cell-rich sublayer (Va) and a cell-poor sublayer (Vb) is clearer ( Vogts-1919 ). See also preSMA.