380 
MR. W. K. PARKER ON THE SKELETON 
above and below, a little behind the large oval fenestra, and at its hind margin, and 
in the rest of the basket-work, the cartilage is soft. Like the pedicle, the short bar 
( h.m .) behind the small, round fenestra is continuous with the parachordal (iv.); it is 
the “ serial homologue ” of the pedicle of the suspensorium, and therefore is the head 
of the hyoid arch (= head of the hyomandibular). Now we begin to feel our way in 
this unenclosed field; we have lit upon some landmarks. One continuous growth 
of cartilage is seen running sinuously, sub-parallel with the axis, from near the fore¬ 
end of the nasal tube ( e.n.t .) to a point beneath the 3rd spinal nerve ( sp.n .). The fore 
part is what I have called the prepalatine “ horn,” or spike ( pr.pa .); it is soft; then 
the hard tract behind it is first palatine (pci.), and then becomes the top of the pterygo- 
quadrate region (pg., q.), passing into the “shoulder” of the hyomandibular (h.m.), the 
fore part of which answers to the wide snaggy part of that bone in an Osseous Fish, 
whilst the hind part corresponds to its “ opercular process ” for the os operculare. 
The hard cartilage of the pterygoid region is separated from that of the palatine in 
front, and the quadrate behind and below, by a narrow soft tract. The soft cartilage 
behind is first inter-hyal (i.hy.) then epi-hyal (e.liy.), and then forms the top of the 1st 
epibranchial (e.hr 1 .) The margining cartilage behind the large oval fenestra, sends back 
a rounded lobe into the hinder fenestra (If 3 .) —a two-horned space ; that lobateband 
is the “ symplectic ” region (sy.) ; it is soft; but the back of the quadrate region, 
into which it passes, is hard. The largest or hindmost two-horned fenestra although 
single below, is broken into two, above, by the main part of the hyoid arch—the 
inter-, epi-, cerato-, and hypo-hyal regions (i.hy., e.hy., c.hy., h.hy.). 
This arched band, bending backwards, and growing downwards and forwards, to pass 
into the huge basal bar, is both wider and thicker than that of an adult Frog, but 
unlike its counterpart in that type it is continuous with the upper or hyomandibular 
part of the arch. Nevertheless, its small width here suggests comparison with the 
hyoid of the adult, and not of the larval Frog, whose broad, short lower hyoid is 
suspended from the suspensorium, beneath the eye-ball, indeed under the front of the 
subocular space. Here the hyoid arch is curved backwards so as to lie, in the middle, 
below the 1st spinal nerve (sp.n.) whilst the arrested quadrate tract (q.) is directly 
below the middle of the auditory capsule, a position attained by the quadrate condyle 
of the Frog soon after metamorphosis. Where the soft cartilage of the hypo-hyal 
region (h.hy.) ends below, there the hard cartilage of the basi-hyal (h.hy?.) begins, but 
there is no joint. 
This continuous hyoid bar, as we have seen, passes over the last, or two-horned 
fenestra dividing it, above, and then riding over it. Above, this hyoid bar passes 
directly into the arched cartilage bounding the hind fenestra ; below, that boundary of 
cartilage passes inside the long hyoid bar, and becomes the symplectic region. From 
its convex margin, behind, this hinder arch gives off two styliform outgrowths. This 
semicircle of soft cartilage, which forms the hinder half of the boundary of the hinder 
