136 



In sonic low buttes on the road to Carter Station, about three miles from 

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

 to Testudb 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 Caiion 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 

 abruptly 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 preserved, is the same as 

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

 shape. 



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

 that the pectoral scute impressions are 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 : 



Inches. 



Length of anterior lobe of the plastron 8 



Breadth at base , 1QJ 



Length of episternal prolongation If 



Breadth of episternal prolongation at base , 5| 



Breadth of episternal prolongation near the extremity 4^ 



Length of entosternal plate 4£ 



Breadth of entosternal plate 5£ 



Length of gular scute impressions 3^ 



Length of humeral scute impressions . 4J 



Length of pectoral scute impressions 3 



Length of pectoral scute impressions where least r , . 2 



