The term area p24d refers to an area at the caudal extreme of the anterior cingulate gyrus that is defined on the basis of internal structure. It is the part of the posterior midcingulate cortex located caudal to area a24c' and rostral to area 23c of Vogt in the human and the macaque ( Vogt-2012 ). In the human it is divided into to subareas: area p24dv in the ventral bank of the cingulate sulcus and area p24dd in the dorsal bank. In the macaque it is distinguishable from area a24c' by: 1) larger cells in the internal pyramidal layer (V), 2) cells of medium size in the lower part of the external pyramidal layer (III), 3) a more prominent columnar pattern, and 4) greater myelinization with a horizontal plexus ( Matelli-1991 ).