Proceeding deep from the most superficial structure, number the following in the correct sequence: (a) _____ walls of vertebral canal (b) _____ dura mater (c) _____ subdural space (d) _____ epidural space (e) _____ pia mater (f) _____ arachnoid membrane (g) _____ subarachnoid space (h) _____ spinal cord