epithalamus

https://doi.org/10.1351/goldbook.11759
Dorsal part of the diencephalon, including the pineal gland and adjacent structures in the roof of the third ventricle.
Source:
PAC, 2015, 87, 841. (IUPAC Glossary of terms used in neurotoxicology (IUPAC Recommendations 2015)) on page 866 [Terms] [Paper]