The brain of the marsupial mole is very small (only 0.8 ml) and the forebrain is dominated by anatomical adaptations for olfaction.  The olfactory bulb, anterior olfactory region, olfactory tubercle and piriform (olfactory) cortex all occupy a large percentage of brain volume, and the rhinal fissure separating olfactory cortex from other areas is situated high on the curvature of the cerebral hemisphere.  The isocortex (6 layered cortex) is very small and confined to the dorsal surface of the cerebral hemisphere.  Functional areas within the isocortex have not been studied physiologically, but there is likely to be a large area devoted to trigeminal somatosensation.  The marsupial mole is blind, so the visual cortex is likely to be rudimentary or absent.  The cerebellum is also simple and the anterior lobe (lobules 1 to 5 of the cerebellar vermis) is so small as to be completely hidden beneath the cerebral hemisphere.  Only the posterior lobe of the cerebellum (lobules 6 to 9 of the cerebellar vermis) is visible externally.  The cerebellar hemispheres are very small, indicating only rudimentary development of cerebro(ponto)cerebellar circuitry.

Schneider C (1968) Contribution to the knowledge on the brain of Notoryctes typhlops. Anatomischer Anzeiger, 123, 1-24.