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Sickle-shaped process of dura mater.

Is a triangular process of the dura mater opposite the internal occipital protuberance. Its base is attached to the middle of the tentorium, and its top or apex bifurcates, to proceed to the sides of the foramen magnum. Its convex surface is towards the cranium, and its concave in the fissure or groove, which separates the two lobes of the cerebellum.

A vertical partition formed by the duplication of the inner layer of the dura which passes down between the hemispheres of the cerebellum.