DERMATEMYDID&. 265 
The xiphiplastra were evidently small bones, but there is no remnant of them preserved. 
The width of the shell of this specimen was about 130 mm. An estimate based on the 
width of the two costal plates shows that the length was approximately 185 mm. The animal 
was therefore somewhat broader relatively than either Stauroty pus salvinii or S. triporcatus. 
So far as known, this species differs from H. saliens in having the bones of the plastron 
less firmly sutured with the peripherals and in having the latter bones, at least those of the 
bridge region, without close suture with the costals. The bridge is much narrower. 
Hoplochelys saliens sp. nov. 
Text-figs. 326, 327. 
The only specimen of this species at present known was found by Dr. ]. L. Wortman 
in 1896, at the head of the Escavada Canyon, Rio Arriba County, New Mexico, in Torrejon 
deposits. It belongs to the American Museum of Natural History and bears the number 
Fics. 326 aND 327.—Hoplochelys saliens. Carapace and plastron of type. 4. Restored 
portions in interrupted lines. 
326. Carapace. 327. Plastron and part of carapace. 
1200. The shell, the only portion preserved, is considerably crusht, but 1s nearly all present. 
The only parts missing are portions of the seventh and eighth costals, the hindermost neurals, 
and some portions of the plastron. Unfortunately for an understanding of the structure of 
the shell much of it was covered by a very refractory matrix, which adhered so closely that it 
had to be ground away to the bone. As a result, it is dificult to determine in many places 
the position of the boundaries of the scutes and sometimes of the sutures. Most of the periph- 
erals, however, have been beautifully weathered out and preserved. 
In form the carapace (fig. 326) was oval, rounded in front and behind, and apparently of 
some considerable elevation. ‘The total length was close to 325 mm.; the width, close to 200 
mm. There was a median keel of moderate height. On each side of this, at a distance of 50 
