The term area 25 of Brodmann (guenon) refers to a subdivision of the cerebral cortex of the guenon defined on the basis of cytoarchitecture and topology ( Brodmann-1909 ). While Brodmann did not include it in the illustration of the guenon cortex, he described it as a portion of area 24 of Brodmann-1905 (guenon) that was homologous to the area 25 of Brodmann (human) and that appears as Brodmann's area 25 in a topologically equivalent location in Vogt-1987. Note that Brodmann earlier assigned the number 25 to area 32 of Brodmann (guenon) ( Brodmann-1905; Mauss-1908 ).