110 TESTUDO. 



three inches three lines broad, and is seven hnes longer. It has bow-shaped sides, 

 converging posteriorly, and its anterior margin is angular. The last vertebral scute 

 is prolonged anteriorly as a cup-shaped process. 



The nuchal scute is five lines broad, and the pygal scute four and a half inches. 



Scutes of the Plastron. — (PI. XXII. 2.) The gular scutes are acute behind, and 

 encroach upon the position of the entosternal plate. 



The pectoral scutes are five and a quarter inches long, and extend posteriorly to 

 the axillary notches. 



The humeral scutes are about an inch long, but expand outwardly, and join the 

 axillary and the fourth and fifth marginal scutes. 



The abdominal scutes are four and a half inches long at their middle, and join 

 the sixth and seventh marginal and the inguinal scutes. 



The femoral scutes are three and a half inches long, and the caudal scutes, where 

 they come into contact, are one and three-quarter inches. 



The axillary scute is situated at the outer side of the notch, and rests upon the 

 inferior angle of the hyosternal plate between the humeral and fourth marginal 

 scutes. The inguinal scute rests upon the hyposternal and seventh marginal plates, 

 between the abdominal and seventh and eighth marginal scutes. 



MEASUREMENTS. 



Inches. 



Estimated length of sternum in the median line ....... 15 



Breadth of sternum ............ 11 



Estimated length of the antero-posterior curve of the carapace .... 22 



Estimated length of transverse curve ......... 22 



Height 6i 



Length of sixth marginal plate .......... 3f 



Height of lateral marginal plates above level of the sternum .... 4 



This species is respectfully dedicated to Mr. Thaddeus A. Culbertson, through 

 whose interested zeal so many of the animal remains of Nebraska have been 

 discovered. 



Testiido lata, Leidy. 



(Plates XXIIL, XXIV. Fig. 1.) 

 Tedndo lata, Leidy: Proc. Acad. Nat. Sci., 1851, v., 173; Owen's Rep. of a Gool. Surv. of Wise, etc., 572. 



This species is the largest of any of the turtles brought from Nebraska, and was 

 obtained by Mr. Thaddeus A. Culbertson. The specimen upon which it was 

 established consists of a carapace and plastron broken into two pieces and otherwise 

 much mutilated. A considerable portion of the carapace is lost, and the sternum 

 is crushed inward from its articulation with the former. 



The form of the species is very much like Testudo Culberisonu, and it may 

 possibly be the same, though it differs in several of its anatomical details. 



In the specimen, the costal plates are united to the marginal plates by close suture. 



The lateral marginal plates are vertical at their upper four-fifths, and those ante- 

 riorly and posteriorly are oblique. 



