<prompt> Not a pa of bony labyrinth?CochleaVestibuleUtricleSemicircular canal  <response>: The inner ear within the petrous pa of temporal bone consists of a membranous labyrinth enclosed in a bony osseous labyrinth. So, inner ear has two pas : ? 1 Bony labyrinth :- Cochlea, Vestibule, Semicircular canals. 2 Membranous labyrinth :- Cochlear duct, utricle, Saccules, three semicircular ducts, and endolymphatic duct sac. 