The term area 31 (macaque) refers to an area of cerebral cortex defined on the basis of cytoarchitecture by Nissl stain in the macaque. It is located in the the rostral part of the precuneus and the most caudal part of the posterior cingulate gyrus ( Vogt-1987 ). It is topologically equivalent to area 31 of Brodmann in the human. For a more recent account of this area see area 31.