Sometimes counted as the thalamus part of the midbrain (diencephalon) and includes the pineal gland and its attachment - the habenula (reins) with nuclei - on the back of the thalamus, i.e. on the pulvinar thalami.
The concept of the epithalamus also includes:
Stria Medullaris thalamiCommissura posterior and
Regio pretectalis.