tentorium

noun2

1. •
   The tentorium cerebelli, an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes.

   • Four dogs with intact tentoriums survived 6 weeks and 8 with sectioned tentoriums survived the same period of time. — 1961
2. •
   The framework of internal supports (a false endoskeleton) within an arthropod head, formed by ingrowths of the exoskeleton called apophyses.

   • In the female of Culex the tentoria arise in front of the border of the occipital foramen and ascend at an angle of twenty-five degrees with the floor of the head. — 1906