16 FIELD COLUMBIAN MusEuM—GEOLOoGY, Vot. II. 
part, where the surface is nearly smooth. The posterior teeth are 
much smaller, as already stated, and are much more closely placed, 
their length varying from six to twelve millimeters. 
The united farze¢a/s form a high, thin, vertical plate of bone, 
convex in outline, about fifty millimeters in height in the middle, and 
only three or four in thickness at the margin, and extending nearly as 
far forward as the pineal foramen. Posteriorly, the sides extend 
downward and outward into a broad flattened process for union with 
the upper ramus of the squamosal. The suture, which is clearly 
apparent, runs downward and outward to the free margin of the 
parietal on each side, beginning in front of the posterior thickened 
bar of the squamosal. Anteriorly this free margin of the parietal is 
continued outward, like the eaves of a roof, to the posterior part of 
the orbit, where it is somewhat roughened; it turns upward here 
rather abruptly. About twenty millimeters above this angle, separated 
by a concave space, is the massive projection for the epipterygoid. 
This bone has been broken away from its attachment on each side, 
and separated for a short distance, leaving a jagged fracture, without 
indications of suture. The upper margin of this thickened epiptery- 
goid protuberance is continued by sutural union with the postfrontal. 
A little in front of the parietal foramen, the bone narrows to a width 
of four or five millimeters,-blended with and continued into the frontal, 
which continues forward to the premaxillary, under which it disap- 
pears. The sutural union for the postfrontal is well marked on the 
right side, beginning a little back of the pineal foramen and running 
downward, outward and backward to the upper margin of the epiptery- 
gold protuberance. Internally the parietals form a broad roof, to 
which is attached, rather far forward, by distinct, oval, obliquely 
placed, V-shaped articular surfaces, the paired supraoccipitals, which 
do not reach quite to the ‘lower free margin of the parietals on 
each side. 
Anteriorly, as already stated, the frontal (?) continues, without 
the slightest indication of a suture with the parietals, forward for forty 
millimeters or so more, as a narrow, flattened surface above, distinctly 
divided by a median suture, to the upper end of the facial processes 
of the premaxille, which articulate on the outer side of the slender 
projection, overlapping the upper surface. How much further the 
bones continue I can not say, but evidently as far forward as the 
anterior end of the orbits. On the right side, the ‘‘ postprefronto- 
nasal’? has been macerated away, so that its relations are clearly 
marked. Below these bones are broader, continuous on each side 
with the free margin of the roof, as already described. The rostrum 
