Reticular membrane

Thin, stiff lamina that extends from the outer hair cells to the Hensen's cells

The reticular membrane is a thin, stiff lamina that extends from the outer hair cells to the Hensen's cells. The RM is composed of "minute-fiddle-shaped cuticular structures" called the phalangeal extensions of the outer hair cells, interspaced with extensions coming from the outer phalangeal cells. The RM separates endolymph in the cochlear duct from underlying corticolymph and perilymph of the scala tympani.

This keyword could refer to multiple things. Here are some suggestions: