532 



ANATOMICAL TECHNOLOGY. 



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Fig. 127. — Diagram op the Cat's Right Ear, Ventral View ; x about 5. 



Canalis semicircularis superior (S.). — Only the beginnings of this are shown. One 

 of them commences in common with the posterior and one with the external canal (§ 1441). 



Canalis semicircularis externa (E.). Only the beginnings of this canal are shown, 

 one of them opening with the superior and one with the posterior canal (§ 1441). 



Cochlea. — This is represented as unrolled and the ventral surface removed so as to 

 expose the scalae and the lamina spiralis (§ 1440). 



Cutis, the skin. — It is continuous over the meatus and becomes very thin as it extends 

 over the membrana tympani to form its ectal layer. 



Fenestra rotunda (Ft. rt.) s. Fenestra cochlea. — In life this is inclosed by a mem- 

 brane. It leads into the scala tympani of the cochlea. 



Fenestra ovalis (Ft. ov.) s. Fenestra vestlbuli. — This is the passage from the tympa- 

 num to the vestibule. In life it is covered by the base of the stapes with its connecting 

 soft parts. 



Incus. — The middle bone of the ear. It is also called anvil and dens molaris (§ 1437). 



Labyrinthus. — This is the third and last or sentient part of the ear. It is often called 

 internal ear. 



Lamina spiralis (Lm. spr.). — This is a plate of bone arising from the modiolus or col- 

 umn of the cochlea, and with its membranous continuation divides the cavity of the cochlea 

 into the two scalae (Fig. 128). 



Ligamentum incudis (Lgt. inc.). — The ligament holding one of the processes of the 

 incus to the wall of the tympanum. 



Malleus. — The first of the small bones of the ear. It is by far the largest of the three. 

 It gains its name from its resemblance to a hammer. Its handle stretches partly across 

 the Mb. tympani. 



Meatus. — The name is written in the meatus ectalis or passage from the exterior to 

 the membrana tympani (§ 1433). 



