The term preoccipital notch refers to a depression in the inferior margin of the cerebral cortex viewed from the side. It marks the boundary between the parietal lobe and the occipital lobe in the human ( Ono-1990 ). The inferior occipital sulcus forms a similar depression in the inferior cortical margin of the macaque ( Martin 2000 ). It marks the boundary between the parietal lobe and the occipital lobe but is not ordinarily referred to as 'preoccipital notch'. Equivalent structures are not found in the smooth cerebral cortex of the rat or mouse ( NeuroNames ).