A A. The dura-matral falx; A*, its attachment to the tentorium.
B. Torcular Herophili.
C. Dura-mater lining the spinal canal.
D D*. Axis vertebra.
E E*. Atlas vertebra.
F F*. Basilar processes of the sphenoid and occipital bones.
G. Petrous part of the temporal bone.
H. Cerebellar fossa.
I I*. Seventh cervical vertebra.
K K*. First rib surrounding the upper part of the pleural sac.