円蓋 脳弓
an arched bundle of white fibers at the base of the brain by which the hippocampus of each hemisphere projects to the contralateral hippocampus and to the thalamus and mamillary bodies
両半球の海馬がそれによって反対側の海馬と視床・乳頭に通じる、脳の下部の白質のアーチ状管束