460 
MR. W. K. PARKER OK THE DEVELOPMENT 
ably longer than the main part, and reaches as far forwards as the cornu trabecuhe 
(Plate 32, figs. 1, 2, ppg., c.tr.) ; it is slightly arcuate. 
The main part of the suspensorium has a thick convex lower, and a sharp concave 
upper, margin. The upper edge has a convex enlargement behind. This is the 
rounded pedicle, which articulates with the basipterygoid process of the trabecula 
(pel., b.pg.). The lower margin becomes concave towards the end; a postero-external, 
triangular process—the otic process—finishes the dorsal end of the suspensorium. 
The sub-convex, oval condyle ( q.c .) looks forward and outward, and fits into the 
scooped hinder face of the articular region of the free mandible. Above its articular 
concavity the mandible sends forwards a large rounded ear of cartilage, convex outside 
(Plate 32, fig. 1, cr.c.) and concave within (fig. 2, cr.c .); this is the coronoid process of 
the mandible. The angular process is a free rounded spur below and behind the 
articular concavity. The rest of the rod (mk.) is terete, and almost straight; it is only 
slightly arched upwards and reaches nearly to the end of the snout. 
The hyoid arch (Plate 32, figs. 1 and 2) has a pier which is curiously and suggestively 
like the suspensorium of the mandible ; but, already, it is relatively much less, being 
now about half as large. It has a pedicle, a free posterior process, a fore-growing 
rounded rod, and an articular facet for the free, inferior arch; the only difference, here, 
is the absence of any borrowed addition at the fore end, such as the pterygoid cartilage 
has in the concrescent palatine. 
The pedicle of the hyoid pier (hm.) is the oblong, articular head, fitting inside the 
oblong concavity under the auditory “ tegmenit has no definite neck. 
The free posterior process (op.p.) is for the opercular bone; it is short and rounded. 
The fore-growing rounded rod is the “ symplectic” region (sy.); it is terete, gently 
curved downwards, blunt at its fore end and enlarged near its origin; it lies anteriorly 
behind (under) the convex edge of the suspensorium. The body of the hyomandibular is 
gently bilobate and fenestrate in the middle (hm.f.); the articular facet for the “inter- 
hyal” (fig. 6, i.hy.) is a scooping between the two convexities of the hind margin 
(Plate 32, fig. 2). 
The rest of the hyoid arch is not in one piece like the mandible, but in three, and 
these have, also, a large double median bar conjugating them. The first of these is a 
small, unciform segment of cartilage, the inter-hyal (fig. 6, i.hy.) ; it is articulated to 
the inner face of the hyomandibular by its hooked end, obliquely, and obliquely also to 
the top of the cerato-hyal by its base. The latter (c.hy.) is half the length and twice 
the thickness of the mandible; it is a rounded rod, swollen near the top, and then 
thickened gradually to its distal end. All but the top and lower concave face is 
ossified. 
The distal concave end is articulated to the top of a globular segment—the hypo- 
hyal ( h.hy ,); this is not ossified. The right and left segments fit into a pair of con¬ 
cavities on the hind face of the glossal piece, or basfhyal ( b.liy .). This is tongue-shaped, 
the sides are parallel, the fore end rounded; it is moderately thick, is essentially 
