The term angular gyrus (ANG) refers to the more posterior of two subdivisions of the inferior parietal lobule identified by dissection in the human ( Carpenter-1983 ) and the macaque ( Martin-2000 ). In the human it is partially separated from the more rostral supramarginal gyrus by the primary intermediate sulcus. Ventrally it surrounds the termination of the the superior temporal sulcus. Caudally its boundary with the occipital lobe is an oblique plane through the parieto-occipital sulcus on the dorsomedial margin of the hemisphere and the preoccipital notch on the ventromedial margin. Its ventral border with the superior temporal gyrus and the middle temporal gyrus is an ill-defined horizontal line that connects the terminal descending limb of the lateral fissure to the rostral boundary of the occipital lobe ( Duvernoy-1992 ). The boundaries in the macaque are somewhat different. It does not surround the termination of the superior temporal sulcus but lies caudal to it. Thus, it is separated from the supramarginal gyrus rostrally by the superior temporal sulcus. It is separated from the occipital lobe caudally by the lunate sulcus of the human. Its ventrolateral border is marked by the inferior occipital sulcus, which separates it from the inferior occipital gyrus. A vertical line from the rostral tip of the inferior occipital sulcus to the lateral fissure marks its ill-defined rostral border with the middle temporal gyrus ( Martin-2000 ). Equivalent structures are not found in the smooth cerebral cortex of the rat or mouse ( NeuroNames ).