Vermis:

the vermis is the tan region above.

the vermis is the tan region above.

midline of the cerebellum; it separates the cerebellum into two cerebellar hemispheres. The vermis is thought to be associated with the ability to maintain upright posture.

Further reading: Know your brain - Cerebellum

Watch this 2-Minute Neuroscience video to learn more about the cerebellum.