rizontal limb (Sylvian fissure).
s.asc, Ascending terminal part of the posterior horizontal limb of
the Sylvianfissure.
p.c.i, Inferior praecentral sulcus.
p.c.s, Superior praecentral sulcus.
r, Fissure of Rolando.
g.s, Superior genu.
g.i, Inferior genu.
d, Sulcus diagonalis.
t^1, Superior temporal sulcus (parallel sulcus).
t^2, Inferior temporal sulcus.
p^1, Inferior postcentral sulcus.
p^2, Superior postcentral sulcus.
p^3, Ramus horizontalis.
p^4, Ramus occipitalis.
s.o.t, Sulcus occipitalis transversus.
occ. lat, Sulcus occipitalis lateralis (the sulcus lunatus of Elliot
Smith).
c.m, Calloso-marginal sulcus.
c.t.r, Inferior transverse furrow.]

The _Temporo-Sphenoidal Lobe_ presents on the outer surface of the
hemisphere three convolutions, arranged in parallel _tiers_ from above
downward, and named _superior, middle and inferior temporal_ gyri. The
fissure which separates the superior and middle of these convolutions
is called the _parallel fissure_ (fig. 9, t^1). The _Occipital Lobe_
also consists from above downwards of three parallel gyri, named
_superior, middle and inferior occipital_. The _Frontal Lobe_ is more
complex; immediately in front of the fissure of Rolando, and forming
indeed its anterior boundary, is a convolution named _ascending
frontal_ or pre-central, which ascends obliquely backward and upward
from the Sylvian to the longitudinal fissure. Springing from the front
of this gyrus, and passing forward to the anterior end of the
cerebrum, are three gyri, arranged in parallel _tiers_ from above
downwards, and named _superior, middle and inferior frontal_ gyri,
which are also prolonged on to the orbital face of the frontal lobe.
The _Parietal Lobe_ is also complex; its most anterior gyrus, named
_ascending parietal_ or post-central, ascends parallel to and
immediately behind the fissure of Rolando. Springing from the upper
end of the back of this gyrus is the supra-parietal lobule, which,
forming the boundary of the longitudinal fissure, extends as far back
as the parieto-occipital fissure; springing from the lower end of the
back of this gyrus is the _supra-marginal_, which forms the upper
boundary of the hinder part of the Sylvian fissure; as this gyrus
occupies the hollow in the parietal bone, which corresponds to the
eminence, it may appropriately be named th