* 
436 MR. W. K. PARKER ON THE SKELETON 
was shown in the last, but the pterygoid band (pg.) is broader. The fibres of the 3rd 
branch of the 5th nerve (V 3 .) have not escaped the layers of the floor at this part. 
21 st Section (Plate 21, fig. 9).—The whole cranio-facial frame is here seen as mere 
patches of cartilage, three pairs of small convexo-concave tracts above, with one large 
trilobate, and two small pyriform, sections below. Here the cranial cavity is large, 
but the cerebrum (C 1 .) is small; the orbito-sphenoids (o.s.) are separated from the 
trabeculse (tr .) by a space ( o.s.f.) wider than the bars themselves. These are bent in 
the opposite direction, the upper are convex outside and the lower concave. The 
pterygoid (pg.) is a gently-arched band; between it and the trabecuke (tr.) the 3rd 
branch of the 5th (V 3 .) is seen lying on the fenestra, ready to enter. The posterior nasal 
canal (p.n.c.) is now without a cartilaginous floor, ready to escape into the pharyngeal 
space ; the cartilages below the buccal cavity (to.) are the basi- and cerato-hyals 
( b.hy., c.hy.). Above these the rising floor of the mouth contains the fimbriated 
intervelar shelf (see Plate 18, fig. 7; and Plate 14, fig. 8). 
22 nd Section (Plate 22, fig. 1).—This shows a pyriform cranial cavity containing the 
fore brain (C 1 .) at its junction with the mid brain. Here the back part of the eye-balls 
(e.) and the orbital muscles are seen, and the posterior nasal canal (p.n.c.) escaping 
through the pituitary space between the trabeculse, which form at this part the 
high alisphenoidal walls (al.s.), in section like a pair of callipers, bent outwards, above, 
like blades, which are connected across the roof by the convex dura mater (d.m.). 
This section is through the hind part of the subocular fenestra ; the pterygoid (pg.) 
is here thick above; the 5th nerve is not figured in this drawing. Below the 
lobulated oral (or buccal) cavity (m.), and between that space and the hyoid apparatus, 
there is a plate of hard cartilage cut across—a thinnish, sinuous tract. This is the 
“ intervelar shelf ” (i.v.s.), cut across behind the fimbriations. Plere the cerato-hyals 
(c.hy,) are much deeper than in the last section. 
23 rd Section (Plate 22, fig. 2).—Here, if anywhere, we have an instructive section, 
made in the pre-auditory or post-pituitary region. The mid and hind brain (C 2 ., see 
also fig. 3, C 3 .) meet here, and the latter is giving off the great trigeminal nerves (V.), 
with their huge gasserian ganglia. These parts are seen in the foramen ovale, under 
the fore face of the auditory capsule (au.) which is surmounted by the alisphenoid 
(al.s.), now turning inwards on to the roof of the skull. Looking at this figure and 
that of the dissected skull (Plate 18), we see that the razor has cut through the 
investing mass (iv.) enclosing the fore part of the notochord (nc.), the pedicles (pd .), the 
back part of the pterygoid (pg.), that part of the suspensorium (or pterygo-palatvM, 
arcade) which gives off the epi-hyal from its hinder margin (see Plate 18, fig. 1, e.hy.). 
Below the basis-cranii, the posterior nasal canal (p.n.c.) has nearly doubled its 
“ bore at some distance below that tube we see, now, not a wide quinquelobate buccal 
cavity, but the plicated opening of the narrow food-pharynx (phi c.), having under it 
the cartilaginous core of the intervelar shelf. Below that shelf we see the hyoid appa¬ 
ratus ; the fissures between that musculo-cartilaginous structure and the shelf form the 
