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E X P L A N A T I O N OF THE TABLES.
T A B L E XXX.
J ^ E P R E S E N T S the OS petrofum diiTedted, after being foftened,
fo as to lliew the diilribution of the portio dura
and portio mollis of the feventh pair, but chiefly of the latter.
FIG. I. Reprefents the back view, and FIG. II. the fore view of the os
petrorum, and parts of the left fide.
FIG. I.
A Tiie inner end of the os petrofum.
B The outer end of the os petrofum.
C The back of the external ear.
D The pofterior end of the fuperior femicircular canal.
• E The fuperior end of the pofterior femicircular canal joining with D.
F The Inferior end of the pofterior femicii-cular canal.
G The portio dura in the meatus auditorius internus, fituated in a half
flieathj formed by the portio mollis.
H The continuation of the portio dura.
I K The two principal parts of the portio mollis. I Ends in the cochlea,
and K in the veftible and fcmicircular canals.
FIG. II.
A The upper and fore part of the cartilage of the external ear.
B The meatus auditorius cut open its whole length.
C The membrane of the drum.
D The malleus.
E The incus.
F The head of the ilapes.
G The
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