Longitudinal fissure

Is a deep groove that separates the two Cerebral hemispheres.

The great longitudinal fissure (or longitudinal cerebral fissure, or longitudinal fissure, or interhemispheric fissure) is the deep groove that separates the two hemispheres of the vertebrate brain.

The falx cerebri

The corpus callosum crosses the medial longitudinal fissure.