Falx cerebri

One of the dural folds, the falx cerebri forms along the mid-sagittal plane where the meningeal dura on both sides separates from the periosteal dura.  The falx cerebri runs within the longitudinal fissure, from the crista galli to the tentorium cerebelli, with its inferior edge just superior to the corpus callosum.  The superior sagittal sinus runs in the superior border of the falx cerebri, and the inferior sagittal sinus runs in its inferior border.