Yes, CORTICES is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, R 1, T 1, I 1, C 3, E 1, S 1.

Is it a valid word?

CORTICES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the layer of unmyelinated neurons (the grey matter) forming the cortex of the cerebrum
the tissue forming the outer layer of an organ or structure in plant or animal
the tissue that surrounds the lens nucleus

Also: cerebral cortex, cerebral mantle, lens cortex.