"Membranous labyrinth of Haliaetus albicilla (White-tailed Eagle), X2.  a,b, cochlea; b, its saccular extremity (or lagena); c, vestibule; g, its utricle; d, anterior of superior vertical semicircular canal; e, external or horizontal semicircular canal; f, posterior of inferior vertical semicircular canal; h, membranous canal leading into aqueduct of the vestibule; k, vascular membrane covering the scala vestibuli; opposite this, at i, are seen the edges of the cartilaginous prisms in the fenestra rotunda; from the edges of these cartilages proceeds the delicate membrane closing the opening of the cochlea (not shown in the fi.)" Elliot Coues, 1884

The Inner Ear of a White-tailed Eagle

"Membranous labyrinth of Haliaetus albicilla (White-tailed Eagle), X2. a,b, cochlea; b, its saccular…

"Membranous labyrinth of Haliaetus albicilla (White-tailed Eagle), X2.  a,b, cochlea; b, its saccular extremity (or lagena); c, vestibule; g, its utricle; d, anterior of superior vertical semicircular canal; e, external or horizontal semicircular canal; f, posterior of inferior vertical semicircular canal; h, membranous canal leading into aqueduct of the vestibule; k, vascular membrane covering the scala vestibuli; opposite this, at i, are seen the edges of the cartilaginous prisms in the fenestra rotunda; from the edges of these cartilages proceeds the delicate membrane closing the opening of the cochlea (not shown in the fi.)" Elliot Coues, 1884

The Inner Ear of an Eagle

"Membranous labyrinth of Haliaetus albicilla (White-tailed Eagle), X2. a,b, cochlea; b, its saccular…

The membranous labyrinth is lodged within the bony labyrinth and has the same general form; it is, however, considerably smaller and is partly separated from the bony walls by a quantity of fluid, the perilymph. In certain places, it is fixed to the walls of the cavity. The membranous labyrinth contains fluid, the endolymph, and on its walls the ramifications of the acoustic nerve are distributed. Within the osseous vestibule, the membranous labyrinth does not quite preserve the form of the bony cavity, but consists of two membranous sacs, the utricle, and the saccule. The membranous labyrinth is also the location for the receptor cells found in the inner ear.

Membranous Labyrinth

The membranous labyrinth is lodged within the bony labyrinth and has the same general form; it is, however,…