The supracallosal gyrus (induseum griseum; gyrus epicallosus) consists of a thin layer of grey matter

Grey matter

Grey matter is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil , glial cells and capillaries. Grey matter contains neural cell bodies, in contrast to white matter, which does not and mostly contains myelinated axon tracts...

 in contact with the dorsal surface of the corpus callosum

Corpus callosum

The corpus callosum , also known as the colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure. It connects the left and right cerebral hemispheres and facilitates interhemispheric communication...

 and continuous laterally with the grey matter

Grey matter

Grey matter is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil , glial cells and capillaries. Grey matter contains neural cell bodies, in contrast to white matter, which does not and mostly contains myelinated axon tracts...

 of the cingulate gyrus.

It contains two longitudinally directed strands of fibers termed respectively the medial and lateral longitudinal striae.

The supracallosal gyrus is prolonged around the splenium

Splenium

The posterior end of the corpus callosum is the thickest part, and is termed the splenium .It overlaps the tela chorioidea of the third ventricle and the mid-brain, and ends in a thick, convex, free border....

 of the corpus callosum as a delicate lamina, the fasciola cinerea, which is continuous below with the fascia dentata hippocampi.