Lateral View of the Midbrain. The left cerebellar hemisphere and vermis were partially removed. The dentate nucleus (Dent. Nucl.) was preserved with the dentatorubral pathway in the superior cerebellar peduncle (Sup. Ped). The lemniscal trigone or Reil’s trigone, which is limited by the lateral mesencephalic sulcus (Lat. Mes. Sulcus) anteriorly, the posterior conjunctival brachium superiorly, and the superior cerebellar peduncle inferiorly, is demonstrated. (Image courtesy of E de Oliveira)