The term area 30 of Mauss refers to a cortical area defined by myeloarchitecture in the portion of the precentral gyrus whose surface constitutes the precentral operculum in the guenon. A footnote indicated that area 30 was correctly depicted in the cortical map but was incorrectly labeled "31" ( Mauss-1908 ). It is labeled "30" in BrainInfo. Brodmann regarded it as topologically homologous to the cytoarchitectonic area 43 of Brodmann (guenon) (Brodmann-1909). The Vogts found no distinctive architectonic area of corresponding location in the guenon ( Vogts-1919 ).