res 
TOXOCHELYID&. 169 
B. F. Mudge, in the Niobrara deposits of Kansas, near the forks of the Smoky Hill River. 
The animal was a large one, since the mandible, from the symphysis to the angle of the jaw, 
measures 157 mm. In 1877, as cited in the synonymy, Professor Cope came into possession 
of 2 nearly complete skulls, which he identified as belonging to 7. latiremis, and these he 
described. These skulls are now in the American Museum and bear respectively the numbers 
1496 (fig. 202) and 1497 (figs. 203, 204). The latter (and probably both specimens) was 
collected somewhere along the Smoky Hill River. A comparison of the lower jaws of these 
skulls with that of the type makes it certain that the former were correctly referred. 
The first publisht figure of the skull of this species was made by Hay, as cited. This 
skull lackt the lower jaw; but a comparison with the skulls described by Cope reveals no 
differences. Other skulls have been figured by Case and Williston, as cited. 
This appears to have been the commonest turtle in the Niobrara beds of Kansas, yet many 
parts of its skeleton remain unknown. ‘The size attained was considerable. If the length of 
the coracoid bore the same relation to the length of the carapace that subsists between these 
bones in Chelydra or Caretta, the carapace must have been about a meter in length. It may be 
remarkt here that the coracoid of Cope’s type was 225 mm. long, that author’s statement 
that it was 250 mm. being incorrect. The ramus of the mandible has a length of 157 mm., so 
that the skull, from the tip of the snout to the occipital condyle, was close to 160 mm. 
The skull of this species is broad posteriorly. 
In front of the quadrates the width is gradually 
reduced, so that the head is wedge-shaped and 
the snout pointed. Altho all the skulls yet found 
are considerably flattened by pressure, it is quite 
certain that the head was rather deprest, more 
like that of Chelydra than like that of any of the 
living Cheloniide. The supraoccipital is long. 
The temporal region is rooft over about as in 
Caretta, and the squamosal appears to have come 
into narrow contact with the parietal. The orbits 
lookt upward and outward, resembling more 
those of Chelydra than those of the Cheloniidz. 
The opening of the anterior nares is large, con- 
trasting strongly with that of 7. stenopora. The 
tympanic cavity did not extend into the squa- 
mosal, but had the stage of development seen in 
the loggerhead. The cutting-edge of the maxilla 
is moderately high anteriorly, but becomes very 
low at the hinder end. As seen in profile, it is convex. There is a rough ridge on the palatine 
near its articulation with the maxilla. The alveolar, or masticatory, surface of the upper jaw is 
somewhat concave from side to side. Including the ridge on the palatine, this surface is not 
so wide as is the fossa containing the choane. There are large posterior palatine foramina. 
The narrowest portion of the palate, across the pterygoids, is rather wide compared with the 
other species, and is flat. More posteriorly each pterygoid bears a groove which is directed 
outward and backward toward the hinder border of the quadrate. 
The lower jaw is relatively weak. The alveolar surface is narrower than in the other 
species in which it has been observed. Fig. 205 represents the lower jaw belonging to 
specimen shown in figures 203 and 204. The outer edge is sharp and rises somewhat above 
the inner edge. The latter rounds off into the inner face of the jaw, which face is in no 
way hidden by the surface referred to. At the symphysis the alveolar surface extends back- 
ward little more than one-half as far as does the lower face of the bone. The tip of the jaw is 
slightly beakt. 
Notwithstanding the fact that a considerable number of skulls of this species have come 
to light, portions of the carapace or plastron are rare. Wieland (as cited) mentions portions 
of the carapace and plastron in Yale University, but he does not describe them. 
The cervical vertebra and some caudals have already been described in the discussion 
of the genus. No other vertebra are known. 
Fic. 206.—Toxochelys latrremis. Scapula and 
coracoid. 4. Redrawn from figures by Case. 
