The term ectocallosal region refers to a narrow band of cortex located in the cingulate gyrus at its junction with the corpus callosum deep in the callosal sulcus. Defined on the basis of internal structure, it has two components: area 33, of the anterior cingulate cortex and midcingulate cortex, and area 26 of the posterior cingulate cortex. The more rostral area 33 is bounded by area 24a, the more caudal area 26 by area 29l. It is not found in the macaque ( Vogt-2012 ).