ndopterygoid and
metapterygoid, seen in lateral view, is distinct in some specimens and
has an associated ridge; these bones appear to be fused in others,
without regard to size. This suture curves dorsally from a point
anterior to the quadrate and passes anterodorsally to the extremity of
the processus ascendens. The suture is visible on the medial side only
near the processus ascendens, for it is covered by a dorsal, toothed
extension of the endopterygoid. The endopterygoid has a smooth lateral
surface; the medial surface is covered with tiny granular teeth, in
characteristic "line and dot" arrangement. The teeth extend onto the
ventral surface of the ventral process.

[Illustration: FIG. 4. _Synaptotylus newelli_ (Hibbard). Restoration of
the palatoquadrate complex, based on K. U. no. 9939, x 5. A, medial
view, B, lateral view.]

Two long, narrow, splintlike bones covered on one surface with granular
teeth are interpreted as ectopterygoids. These are 13.0 and 16.0 mm.
long and each is 1.5 mm. wide. Orientation of these is unknown, but they
probably fitted against the ventral surface of the ventral process of
the endopterygoid (Moy-Thomas, 1937:fig. 5).

[Illustration: FIG. 5. _Synaptotylus newelli_ (Hibbard). A, ceratohyal,
lateral (?) view, based on K. U. nos. 11429 and 11457, x 5. B, urohyal,
based on K. U. no. 11457, x 5.]

The metapterygoid has a smooth surface in both views. The dorsal edge
has a thickened, flared margin that presumably articulated with the
antotic process of the basisphenoid. No articular surface for the
basipterygoid process has been observed.

The quadrate is distinct and closely applied to the posteroventral
margin of the complex. In medial view the margin is nearly straight and
continues to the ventral edge. The ventral surface is thickened and
forms a rounded, knoblike articular surface. In lateral view the surface
is smooth; the anterior margin is irregular (or perhaps broken on all
specimens), and proceeds in an irregular convex curve from the posterior
to the ventral margin.

The general shape of the palatoquadrate complex is most nearly like that
of _Rhabdoderma elegans_ (Moy-Thomas, 1937:fig. 5). The orientation of
the complex in the living fish was probably oblique, with the processus
ascendens nearly vertical, the quadrate oblique, and the ventral process
of the endopterygoid extending dorsoanteriorly and articulating with the
parasphenoid.

Of the hyoid arch only the cerat