The term area 10a of Vogts refers to a subdivision of area 10 of Brodmann (guenon). Defined on the basis of cytoarchitecture and myeloarchitecture it is the part of area 10 located rostral to area 8 gamma of Vogts. It differs from area 8 gamma in that the molecular layer of the cerebral cortex (I) is narrower, the internal granular layer (IV) is narrower and less cellular, the internal pyramidal layer (V) is wider with a less dense distribution of nerve cells and a more distinct division into sublayers: a narrower more densely populated Va and a wider less densely populated Vb. The multiform layer (VI) has fewer cells. The rostral boundary of area 10a was ambiguous in the map of the Vogts' areas ( Vogts-1919 ).