scala ves·tib·u·li 
(vĕ-stĭbyə-lī′)
(vĕ-stĭbyə-lī′)n. pl. scalae ves·tib·u·lo·rum (-lôrəm)
The uppermost of the three divisions of the spiral cavity winding around the modiolus of the cochlea in the inner ear. It is filled with perilymph and receives vibrations from the stapes.
[New Latin scāla vestibulī : Latin scāla, staircase (from its spiral structure ) + Latin vestibulī, genitive of vestibulum, vestibule.]