(a) gyri; (b) sulci (furrow between gyri); (c) corpus callosum (body); (d) genu of corpus callosum; (e) corpus callosum, splenium; (f) septum pellucidum; (g) fornix (body); (h) fornix column; (i) foramen of Munro; (k) thalamus (optic thalamus); (l) anterior commissure; (m) interthalamic adhesion; (n) posterior commissure; (o) pineal gland; (p) stalk of pineal gland (crus glandulae pinealis); (q) corpora quadrigemina; (r) pons Varoli; (s) aqueduct of Sylvius; (t) tuber cinereum; (u) infundibulum; (v) pituitary gland (hypophysis); (w) optic chiasm; (x) optic nerve; (y) fourth ventricle; (z) mamillary body.