182 
MR. W. K. PARKER OK THE STRUCTURE AND 
nerve (8 ) ; below the two bony masses is the huge deep fossa for the stapedial and inter- 
stapedial cartilages (st., it.st.) ; and below this hollow is the rounded unossified opisthotic 
region (op.), to which the stylo-hyal (st.h.) has at last become closely attached. The 
broad occipital condyle (o.c.) is capped with persistent cartilage; and the exoccipital 
bony mass mounts up above the condyle into the supraoccipital region, and descends 
below into the base of the skull. 
The endoskeletal part of the premaxillary region has been described with the nose- 
capsule ; we now come to the lateral regions. There has been no tendency to segmentation 
of the “ superpalatal ” bar from the prefrontal mass (Plate IX. figs. 6, 7, s.pa., pr.f.) ; and 
the “ prepalatal ” (p.pa.) is now a flat triangular projection slightly affected by endostosis, 
continuous with that of the rest of the bar. The constriction between the “ postpalatal ” 
and pterygoid regions is now obliterated (pt.pa., p.g.) ; the ectosteal palatal lamina 
(fig. 7) has not increased in size relatively ; thus most of the palatal region is left unarmed 
with bony matter. 
The “ subocular fenestra ” (s.o.f.) is a large ellipsoidal space made slightly reniform 
by the bulging of the cranial side-wall ; outside it is bounded by the elegantly arcuate 
anterior part of the pterygoid (pg.). 
There is still a very solid core of hyaline cartilage to the pterygoid, the “ Anoura ” 
being very remarkable in that the ectosteal plates show, for the most part, so feeble an 
affinity for the cartilage within, and even for the endosteal bone into which the carti- 
lage is changed (‘ Shoulder-girdle and Sternum,’ pis. 5-8, pp. 66-89). This unchanged 
core is most exposed on the upper surface (Plate IX. fig. 6). The metapterygoid bony 
spur ( m.pg .) is now small and placed anterior to the triangular “ infrahyomandibular ” 
(• i.li.m .) ; behind the latter is the deep recess which bounds the “ Eustachian tube;” and 
then the pterygoid grows downwards, backwards, and outwards, strongly clamping the 
suspensorium (figs. 1-7); this posterior portion of the “ectosteal pterygoid” is a super- 
erogatory growth of fibrous bone, its proper cartilaginous axis ending at the front margin 
of the suspensorium. 
The posterior part of the bony pterygoid is best seen from behind (fig. 4 ,p.g.), in which 
view we can most readily understand the manner in which the suspensorium is continuous 
with the skull in its metapterygoid or antero-external portion, and how it glides on the 
skull by its postero-internal portion, the infrahyomandibular ( mpg ., i.hm.). 
The metapterygoid portion of the suspensorium is overhung by an eave of cartilage 
from the projecting periotic capsule ; this eave is cut through in front of the suspensorium 
in the section (Plate X. fig. 8) ; and under the shadow of this eave the “ extrastapedial ” 
spatula turns forwards to receive, on its outer surface, the fibres of the “ membrana tym- 
pani ” (Plate IX. fig. 3, a.t., e.st.). The cartilaginous eave is tiled over by the embracing 
supratemporal part of the squamosal, the projecting edge of which forms a strong ridge 
for the attachment of the ends of the cartilaginous “annulus,” which have now met each 
other (Plate IX. fig. 3, a.t., s.t.). 
The quadrate angle of the subocular arch now projects almost as much backwards as 
