The term area 16 of Brodmann (guenon) refers to a subdivision of the cerebral cortex of the guenon defined on the basis of cytoarchitecture. It is a relatively undifferentiated cortical area that Brodmann regarded as part of the insula because of the relation of its innermost multiform layer (VI) with the claustrum. The laminar organization of cortex is almost totally lacking. The molecular layer of the cerebral cortex (I) is wide as in area 15 of Brodmann. The space between layer I and layer VI is composed of a mixture of pyramidal cells and spindle cells with no significant number of granule cells. Pyramidal cells clump in the outer part to form glomeruli similar to those seen in some of the olfactory cortex ( Brodmann-1905 ). Area 16 of Brodmann is topologically equivalent to the agranular orbitofrontal cortex in the macaque. It and area 15 of Brodmann together are most nearly equivalent to the insulo-orbital cortex of later architectonic segmentations.