oncave anterior margin bears
pores of the postorbital part of the infraorbital line. Ornamentation
consists of widely spaced, coarse tubercles.

Part of one squamosal is preserved. It is somewhat triangular and its
apex is ventral. This bone is associated with the postorbital,
subopercular and lacrimojugal on no. 788. The preopercular sensory line
passes down the curving ventral margin of this bone, and extends
ventrally onto a narrow projection. A low ridge, nearly vertical, passes
dorsally from about mid-point of the canal to the dorsal portion. The
anterior margin is nearly straight, the ventral margin is concave, and
the dorsal margin is convex dorsally but may be incomplete. Perhaps the
squamosal and preopercular are fused. The surface appears smooth; the
view may be of the medial side. The squamosal of _R. elegans_ is nearly
triangular and notably different from that of _Synaptotylus newelli_.

The subopercular (fig. 3) shows closely spaced tubercles on the lateral
surface. The bone is an elongated, irregular triangle with the apex
pointing anterodorsally. The margins are incomplete, except for the
concave, curving anterior margin.

Numerous operculars (fig. 3) occur in the suite of specimens, both
isolated and nearly in place. Each is subtriangular; the apex of the
triangle is ventral. A slight convexity projects from the anterodorsal
border. The posterior margin is broadly but shallowly indented.
Otherwise the margins are smooth. Maximum height ranges from 8.0 to 11.0
mm., and maximum width from 8.0 to 13.0 mm. Ornamentation varies from a
few widely spaced, randomly oriented tubercles to closely spaced
tubercles merging posteriorly into striae. On some specimens these are
parallel to the dorsal border, and oblique in the central portion. On
the posterior margins of several operculars the striae break up into
tubercles. A few operculars have closely spaced tubercles over much of
the surface. The internal surface is smooth.

_Visceral skeleton_

The palatoquadrate complex, best seen on K. U. no. 9939 (fig. 4),
consists of endopterygoid, ectopterygoid, metapterygoid and quadrate. No
trace of epipterygoids, dermopalatines or autopalatines, such as
Moy-Thomas (1937:392, fig. 5) described for _Rhabdoderma_, has been
observed.

The endopterygoid has a long, ventral, anteriorly-directed process, and
an anterodorsal process that meets the metapterygoid in forming the
processus ascendens. The suture between the e