. On the anatomy of vertebrates. Vertebrates; Anatomy, Comparative; 1866. ORGAN OF HEARING IN REPTILES. 349 230. Orgiiii of bfnring-, Crocodile. flap of the integument, and accurately closing the divided into two compartments by a double cartilaginous septum, lb. h, except at the apex, where they communicate; whilst, at the base, one compartment, ' scala vestibuli,' communicates with the Ycstibule, the other, ' scala tympani,' by a small orifice (foramen cochlea3, sen rotundum), with the tympanic cavity, in the dry skull, but closed by membrane in the living animal. The cochlear division of th
. On the anatomy of vertebrates. Vertebrates; Anatomy, Comparative; 1866. ORGAN OF HEARING IN REPTILES. 349 230. Orgiiii of bfnring-, Crocodile. flap of the integument, and accurately closing the divided into two compartments by a double cartilaginous septum, lb. h, except at the apex, where they communicate; whilst, at the base, one compartment, ' scala vestibuli,' communicates with the Ycstibule, the other, ' scala tympani,' by a small orifice (foramen cochlea3, sen rotundum), with the tympanic cavity, in the dry skull, but closed by membrane in the living animal. The cochlear division of the acoustic nerve is shown at v, fig. The semicircular canals are small com- pared with those of fishes : c is the anterior perpendicular, d the pos- terior perpendicular, and e the ex- ternal or horizontal, canal which curves over the 'foramen ovale,'/. The membrana tympani, g, is lodged at the bottom of a deep fissure, and is protected by an opercular h, fitting to a smaller fold below, i, l^assage. This is the sole approach to an external ear known in existing Ref)tLHa. The ear-drum is inclined downward and outward, adapted to the reception of sound from alcove, and also to the position of the overhanging flap. The gristly rei^resen- tation of the malleus, k, is well-marked, and the ear-drum is thickened at its place of attachment: the columellar part of the stapes, I, extends obliquely downward to the foramen ovale, sen vestibuli, f. The tympanic cavity, in, is singularly extended by air-cells, not only developed in the mastoid, but in the basi-, par-, and super-occipitals, fig. 94, 3, in the alisphenoid and parietal, ib. 7, bones. The communications between the tympanic cavity and fauces are more comj)lex than in other animals,' although the eustachian fauoial opening, n, is single, median, and common to both ears. It is situated a short way behind the pos- terior nostril; and from it is continued a median, o, and two lateral, p, canals. The median canal rises and ent
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Keywords: ., bookauthorowenrichard18041892, bookcentury1800, bookdecade1860
