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BONES. 127

inferior surface of the great wing of the sphenoid, back of, and a little
external to, the pterygoid process. This foramen transmits the inferior
maxillary nerve and the lesser meningeal artery.
Seyenth : the Foramen Sjnnosum, situated behind and externally to
the foramen oyale in the inferior surface of the great wing of the sphe-
,noid bone. It transmits the middle meningeal artery.
Eighth : the tSpinout^ Froce^n of the SpJienoid Bone, which is the ])os-
terior external angle of the inferior surface. This process gives origin
to the laxator tympani muscle.
Ninth : the Glenoid i'o.y.s-a, situated external to the spinous process of
the sphenoid bone. This fossa is a large oval depression which receives
the condyle of the inferior maxillary bone in the articulated skull, and
also the superior portion of the parotid gland.
Tenth : the Extenml Auditori/ Ilecdiii^, situated behind the })osterior
external boundary of the glenoid fossa.
Eleventh : the Glenoid Fi.ssure, which passes inward and forward
through the centre of the glenoid fossa.
Twelfth : the Eustachian Sidcus, which is between the inner extremity
of the glenoid fissure and the body of the sphenoid bone. The sides of
this sulcus are formed by part of the petrous portion of the temporal
and the great wing of the sphenoid bone, its internal portion being
frequently incomplete.
Thirteenth : the Middle Laeereded Foramen, A\hich is situated between
the apex of the petrous portion of the temporal and the body of the
sphenoid bone. In the recent state it is filled up by fibro-cartilage.
Its size varies in different skulls, and occasionally it is found filled with
bone.
Fourteenth : the Petro-basilar Groove, between the petrous portion
of the temporal and the basilar process of the occipital bones. This
groove in the recent state is filled with fibrous tissue.
Fifteenth : the Posterior Lacerated Foramen, which extends back-
ward and outward from the petro-basilar groove. This foramen is
formed by the union of the jugular fossie of the temporal and occip-
ital bones. It transmits the jugular vein and the ninth, tenth, and
eleventh nerves, a septum of bone often separating the vein from
the nerves.
Sixteenth : the Opening for the Cewotid Canal is situated on the under
surface of the petrous portion of the temporal bone, just anterior to the
posterior lacerated foramen.
Seventeenth : the Digastric Groove, situated on the internal surface
of the mastoid portion of the temporal bone. It is long, deep, and
narrow, for the origin of the digastric muscle.
Eighteenth: the" Stylo-mastoid Foramen, situated at the anterior
extremity of the digastric groove at the base of the styloid process of
the temporal bone. This foramen gives exit to the seventh or facial
nerve.
Nineteenth : the Styloid Process of the Temporal Bone extends do^n-
ward from a point just anterior to the stylo-mastoid foramen. The base
of this process is surrounded by what is termed the vaginal process.
Twentieth : the Pharyngeal Spine is a small tubercle situated about
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