106 



In some low Ijuttes on the road to Carter Station, about three miles from 

 Fort Bridger, Dr. Carter found a large turtle, which I viewed as jjertainiiig 

 to Tcstudo Corsoni. As it lay partially exposed it measured about 2 feet 4 

 inches in length, and approximated 2 feet in breadth. It was so much 

 broken that in the attempt to remove it, it fell into a multitude of fragments. 



In Dry Creek Canon we discovered another turtle, which I viewed as T. 

 Corsoni. The shell was in great part decomposed, but the rock which had 

 occupied the interior still preserved its form. From this cast we estimated 

 the shell to measure 28 inches long, 20 inches broad, and 14 inches high. 



Another specimen of a large turtle, discovered by Dr. Corson on the buttes 

 of Dry Creek, consisted of fragments of a plastron with a few marginal plates 

 of the carapace. The plastron, of which we have been enabled to restore 

 the greater part of the anterior lobe, presents peculiarity enough to pertain 

 to a distinct species from T. Corsoni. It was about the size and proportions 

 of the plastron attributed to the latter, but the episternals are neither so 

 aljruptly nor so much prolonged as in the former specimens, and the front 

 part, as represented in Fig. 3, Plate XXX, is decidedly notched. The under 

 surface of the extremity of the anterior lobe is flatter. 



The bony construction of the plastron, so far as preservecf, is the same as 

 in the former specimens, and the entosternal is nearly of the same size and 

 hape. 



The scute impressions are also the same as in the former specimens, except 

 that the pectoral scute impressions arc nearly twice as long. 



Fragments from the back lobe of the plastron retaining the bottom of the 

 poststernal notch indicate this to be more acute than in the former speci- 

 mens. 



The measurements of the specimen are as follows : 



lutbes. 



Length of anterior lobe of the plastrou 8 



Breadth at base ]0J 



Length of episternal prolongation ] ;i 



Breadth of episternal prolongation at base 5i 



Breadth of episternal prolongation near the extremity 4^ 



Length of entosternal plate 4J 



Breadth of entosternal plate 5J 



Length of gular scute imi^ressions 3^ 



Length of humeral scute impressions 4J 



Length of pectoral scute impressions " 3 



Length of pectoral scute impressions where least , . . li 



s 



