Rostrum of corpus callosum

The anterior end of the corpus callosum is named the genu, and is bent downward and backward in front of the septum pellucidum; diminishing rapidly in thickness, it is prolonged backward under the name of the rostrum, and is connected below with the lamina terminalis, which stretches from the interventricular foramen to the recess at the base of the optic stalk.

The anterior cerebral arteries are in contact with the under surface of the rostrum; they then arch over the front of the genu, and are carried backward above the body of the corpus callosum.