as a maximum width of 1.3
mm.

The lacrimal fills the remaining rim of the narial opening between the
nasal and maxillary, and extends to the anterior edge of the orbit. The
length, from naris to orbit, is 4.2 mm.; the width ranges from 1.0 mm.
anteriorly to 2.5 mm. posteriorly.

[Illustration: FIG. 2. _Hesperoherpeton garnettense_ Peabody. Skull,
lateral view, showing relatively large orbit and absence of smaller
circumorbital bones. KU 10295, x 4.]

The external naris is approximately 1.0 mm. in diameter. It is slightly
anterodorsal to the internal naris and 4.0 mm. lateral to the midline.

The dorsal margin of the orbit appears to be formed by the frontal. The
anterior part of this margin, however, may be formed by a prefrontal,
which is not clearly set off by a suture. The frontal extends 3.8 mm.
in the midline, and anteriorly and laterally borders the nasal and
lacrimal, respectively. A faint pattern of pitting radiates on the
surface from the center of ossification of the frontal. There is also a
pit indicating the presence of a supraorbital sensory pore.

The parietal bones enclose the pineal opening, approximately 2.5 mm.
posterior to the suture with the frontal. The foramen is about 0.5 mm.
in diameter. Laterally the parietal meets the medial angle of the
postorbital and the medial border of the supratemporal. No bone of this
animal shows the deep pitting and heavy ornamentation characteristic of
many primitive Amphibia.

The postorbital meets the anterolateral corner of the parietal for a
distance of 0.5 mm., the anterior edge bordering the frontal bone and
the orbit for a combined distance of about 3.0 mm. The lateral margin
is slightly convex, and is probably interrupted behind by the anterior
point of the tabular. Medially, the concave margin of the postorbital
meets the supratemporal for about 3.5 mm.

The supratemporal is thus wedge-shaped and located between the parietal
and the postorbital. The posterior edge of the supratemporal protrudes
as a convex border slightly behind the end of the parietal, and
measures 3.0 mm. around the curve to the parietal suture.

[Illustration: FIG. 3. _Hesperoherpeton garnettense_ Peabody. A, left
squamosal, internal surface. B, left squamosal, external surface. C,
right tabular internal surface. D, right tabular, external surface. KU
10295, all x 4.]

The squamosal (Fig. 3 A, B) is a large, somewhat rectangular bone
extending from the back of the orbit to the