a progressive ossification of neural
arches toward their dorsal ends, and of intercentra around the
notochord, with probable fusion of the intercentra and neural arches in
the posterior part of the trunk. The notochord seems to have been
slightly constricted by the intercentra, but not interrupted.

RIBS

The proximal ends of the ribs expand dorsoventrally to a width
approximately four times that of their slender shafts. The tuberculum
and capitulum on each of the trunk ribs are separated only by a shallow
concavity. These two articular surfaces are so situated that the rib
must tilt downward from the horizontal plane. The shaft flares
terminally in some ribs, and the distal end is convex. Ribs in the
trunk region differ little if any in size. Five that can be measured
vary in length from 5.0 to 7.0 mm. One short, bent rib 3.5 mm. long
perhaps is sacral or caudal.

PECTORAL GIRDLE (Figs. 8, 9, 10)

The right scapulocoracoid is almost complete, and the left one is
present but partly broken into three pieces, somewhat pushed out of
position. With the advantage of this new material, we may comment on
the scapulocoracoid of _H. garnettense_ as described by Peabody (1958).
In size and contour, the slight differences between the type (KU 9976)
and the new skeleton (KU 10295) are considered to be no more than
individual variation. We have redrawn the type (Fig. 8) in order to
show the resemblances more clearly.

The small sections that were missing from the type are present in KU
10295. The jagged edge directly posterior to the area occupied by the
neural arch in the type extends 0.5 mm. farther back in our specimen.
The angle formed between the recurved dorsal ramus and the edge of the
ventral flange is seen in our specimen to be less than 90 deg.. The glenoid
fossa, appearing as a concave articular surface for the cap of the
humerus, was in part covered by cartilage and shows as "unfinished"
bone (Peabody, 1958, p. 572); this area is more oval than triangular,
as Peabody thought. The obstruction of a clear view of this part of the
type is the result of the accidental position of a neural arch. The
raised portion immediately dorsal to the glenoid fossa exhibits an
unfinished surface, suggesting the presence of either cartilage or a
ligament.

[Illustration: FIG. 8. _Hesperoherpeton garnettense_ Peabody. Type
specimen redrawn. Right scapulocoracoid in external view (at left), and
internal view (at right). KU 9976,