The term medial longitudinal stria refers to the more medial of two thin bundles of myelinated fibers oriented longitudinally near the midline on the dorsal surface of the corpus callosum in the human ( Riley-1943 ). Identified on the basis of topology and myelin stain, it extends from the fasciolar gyrus caudally to the paraterminal gyrus rostrally. The more lateral bundIe is the lateral longitudinal stria. The two together with the indusium griseum constitute the supracallosal gyrus.