The term area 11 of Brodmann (guenon) refers to a subdivision of the frontal lobe of the guenon defined on the basis of cytoarchitecture ( Brodmann-1905 ). Distinctive features: area 11 lacks an internal granular layer (IV); larger pyramidal cells of sublayer 3b of the external pyramidal layer (III) merge with a denser self-contained collection of cells in the internal pyramidal layer (V); similar to area 10 of Brodmann (guenon) is the presence in the multiform layer (VI) of trains of cells oriented parallel to the cortical surface separated by acellular fiber bundles; a thick molecular layer of the cerebral cortex (I); a relatively narrow overall cortical thickness; and a gradual transition from the multiform layer (VI) to the subcortical white matter.