174 MR. W. K. PARKER ON THE STRUCTURE AND 
incus (7.),* is seen to be nearer to the eye than the stapes, the fore margin 
of which lay somewhat back. Here part of both the parietal and squamosal 
(p., sg.) are shown and also the orbitosphenoidal band, now the supra-auditory, 
where it rests upon the crest of the auditory capsule. Below that crest the 
thick outer edge of the capsule is seen forming the tegmen tympani (¢.ty.) under which 
the body of the incus (7) is shown, in front of the stapes. The canal for the facial 
nerve (VII.), is cut through, outside the cochlea (ch/.), and under the cochlea part of 
the vestibule is laid open just at the fore end of the fenestra ovalis. Under the 
incus (¢.) a small cavity is seen, this is the hind part of the tympanic cavity which 
is very small even further forwards; there is very much soft tissue filling in the 
spaces here. Under the auditory capsule, on the outside, the epihyal is seen (see 
also Plate 25, fig. 2, e.dy.), and to it is articulated the top of the ceratohyal (e.hy.).t 
20th Section (Plate 24, fig. 10).—The description just given may serve for the 
next section, but this being a little further back the hole in the stapes (s¢.) has been 
reached. In this the facial nerve (VII.) was found in two places, besides the one 
above, owing to the curve it takes in its course. The cochlea is most open on the left 
side, and on the right it is cut through at its proximal part, and the vestibule is 
opened through the fenestra ovalis. 
21st Section (Plate 24, tig. 11).—This next oblique section shows the malleus (i.) 
on the right side, behind its manubrium ; below it is the tympani cavity (c.ty.) and the 
facial nerve and geniculate ganglion (VII, VIII.) ave seen above it. There is still a 
considerable space between the auditory capsule (chl.), and the thick oblong section 
of the basis cranii, now the basioccipital (b.0.). The hyod bar (e.hy.) is cut through 
obliquely, and under it the facial part of the seventh nerve (VIL.) is shown. On the 
left side the supra-auditory cartilage (s.a.c.) is continuous with the capsule, and go also 
is the basioccipital plate (b.0.). Here the razor passed through the meatus internus 
(VIIT.), and the fenestra ovalis ; in the latter the stapes (st.) is shown exactly through 
its middle, with the stapedial artery (st.a.) threading it. The top of the epihyal only 
is shown at the back of the tegmen (t.ty,), just where the short crus of the incus is 
articulated, Under the stapes a small cavity is seen, part of the tympanic (c.ty.). 
22nd Section (Plate 24, fig. 12).—This also is oblique, but is two or three sections 
further back than that shown on the last figure. Here the right side shows the 
stapes (s¢.) cut across with the stapedial artery (st.a.) threading it ; here, however, we 
vet a section of the auditory capsule showing both the fenestra, the oval and the round 
(fs.0., f.7.),and this also shows the meatus internus (VIIL). The tegmen tympani 
(t.ty.)f is deeper here, and the inner edge of the capsule (ch/.) is seen to come down 
upon the basal plate (b.0.) to unite with it. This plate is fusiform in section and 
has the basilar artery (b.a.) upon it, and the notochord (n.c.) grooving its lower 
* The line of reference in this figure is too short and does not reach the incus. 
+ In this figure for i read ehy., and for e.hy. vead c.hy. 
¢ The line of reference passes downwards instead of across. 
