The term annectant gyrus refers to a buried convolution of cerebral cortex located in the floor of the deep intraparietal sulcus of the macaque ( Kappers-1960 ). It also extends a short way along the floor of the lunate sulcus of the human at its junction with the intraparietal sulcus ( Martin-2000; Dubach-2008 ). In the human, small topologically similar but unnamed convolutions appear in the depths of the intraparietal sulcus ( Duvernoy-1992; Mai-1997 ). Equivalent structures are not found in the smooth cerebral cortex of the rat or mouse ( NeuroNames ).