196 KANSAS ACADEMY OF SCIENCE. 
The vomer is stout, broad and concave anteriorly; laterally, the anterior ex- 
panded portion joins the maxillz in a rugose suture, expanding backward to join 
the anterior end of the palatines, as in Toxochelys, excluding the maxille from 
the narial border. At the beginning of the narial opening the bone rapidly 
narrows to less than half of its greatest width, and gently widens to its union 
with the pterygoids. Between the nares the bone forms a stout, narrow ridge, 
which becomes nearly obsolete at its junction with the pterygoids. 
The palatines are broadly connected with the maxille. From the rugose 
ridge already mentioned, continuing the border of the maxilla forward, the bone 
turns upward, and is thinner, forming the shallow concave groove of the nares. 
They join the vomer broadly in a nearly straight suture, and posteriorly the 
pterygoids on the outer part of the transverse suture. 
The pterygoids have the median suture nearly obliterated. They are grooved 
shallowly in the middle. Laterally they send out a broad, ectopterygoid process, 
for union with the maxillze: and jugals. Near the middle posteriorly there is a 
vertical flattened surface to abut against the mandibles. The large, oval, palatine 
foramen is enclosed nearly wholly between these two bones, the free maxillary 
border showing only for two or three millimeters. Posteriorly the pterygoids join 
the quadrates by a flattened process; in the middle by a V-shaped suture, the 
basisphenoid. Near the end of the arms of the V there is a small foramen on 
each side. 
The basisphenoid shows a small, triangular, nearly smooth surface between 
the pterygoids and basioccipital. 
The basioccipital surface forms a shallow fossa. The occipital condyle is 
bipartite. 
The external nares are much broader than high; their sides, formed by the 
maxille, are nearly parallel; the lower border, formed by the premaxillaries, is 
biconcave, with a median tubercle; the upper border, formed by the prefrontals, 
has a strong convexity from near the rounded angles; on the floor a narrow, well- 
marked groove runs from each palatine foramen forward nearly to the free mar- 
gin. 
The orbits are obliquely ovate in outline and look obliquely upward, outward, 
and forward. On the anterior part below, the opening of the nares is marked 
by a sharp ridge in the palatines; under the posterior part is seen the larger part 
of the palatine foramina. 
The mandibles are remarkable for their stoutness and breadth. The alveolar 
surface is shallowly concave, longitudinally and transversely, and narrow at the 
symphysis, which is marked by a prominent rugose ridge. Posteriorly the sur- 
face rises very high into the coronary process, beyond which the specimen de- 
scribed is for the most part wanting. Below, the part described forms a broad, 
gently convex surface, marked by numerous small foramina. Internally there is 
a well-marked groove below the thinned inner border of the alveolar surface. In 
the middle, in front, the surface forms a rather broad, trough-like concavity. 
The symphysis is elongate. 
As a whole, the skull is remarkable for its broad, strongly convex form, its 
extremely deep alveolar margin of the maxillz, its rostral protuberance, and the 
broad, flattened and strong maxillz, together with the strong venous markings 
of its surface. While the posterior part of the described skull is injured, it was 
undoubtedly roofed over, as in Toxochelys. While the general relations of the 
bones are nearly as in Toxwochelys, the proportions and forms of the different 
parts are very different, all indicating distinctly different habits. 
Carapace. About three-fifths of the carapace is preserved. In the drawing 
