( 807 ) 
ef the Os Petrofum, as 
it was feparated from above 
the Tympanum and other 
farts of the inner Ear. 
a a The ragged Margine of 
the Bone. 
bb The upper part of the 
Caviras Tympani. 
c The Foramen Ov'ale. 
d The Frotuberance in which 
the Labyrinth and Coch- 
lea are lodg'd. 
e The Orifice of the hard 
portion of ?^^NervusAu- 
ditorius. 
Fig. IV. 
Reprefents the Malleolus a 
lone in its true dmenfions. 
I The Protuberant Head. 
z The Semicircular Sinus he<. 
iwixt it and the Margin 
^ The Sinus which receives 
the head of the Incus. 
4 The angle below the Sinus 
for the head of the Incus, 
y The angle where the Ma- 
nub ium Malleoli begins. 
6 The Manubrium Malleoli. 
Fig.V. 
Reprefents the Incus. 
I The head of the Incus. 
X The Sinus or neck of the 
Incus*. 
3 Two Apophyfes. 
4 A long protuberance with 
the Sinus for the Os qua- 
drangulare at its extre- 
mity. 
Fig. VI. 
Reprefents the Stapes. 
I The fmall part of the 
Scapes, where it is articn^ 
lated with the Incus, with 
a Sinus at its extremity, 
being the other half of the 
Cavity for the Os qua* 
drangulare. 
1 z Two fmall portions of 
the Stapes, where it is ar- 
ticulated with the Bafis. , 
} The Bafis of the Scapes 
feparated. 
4 The whole S'^^L'gQS. 
Fig.VW. 
The Malleolus and Incus, 
joind together, with their,, 
lower. fide turdd. up. 
i The Malleolus. 
X Its articulation with the. 
Incus. 
3 The Incus. 
4 7 /^^ Manubrium Malleolr.. 
y A point of the Incus,^ 
• fram’d hy the- other two^ 
froduFtknu. 
6. The 
