382 FOSSIL TURTLES OF NORTH AMERICA. 



midline for the space of 85 mm. The sulcus between these and the anals is directed outward 

 and backward. Where it crosses the edge of the xiphiplastron there is a considerable notch. 

 The anals have a fore-and-aft extent of about 70 mm. and a breadth of 103 mm. each. 



The sulcus between the plastral and the marginal scutes runs above the lower peripheral 

 suture, as it does in Testudo. 



There is a large inguinal scute, but there is no axillary scute, or a very obscure one. 



On the bridge are three considerable bosses, separated by the sulci in front of and behind 

 the abdominal scute. 



In endeavoring to find characters to distinguish this species from the others that have been 

 described we miss first the epiplastral lip. From H. majusculus, of the Wasatch, it differs in 

 having the bridge longer relatively to the hinder lobe. In the Wasatch species the hinder lobe 

 forms about 85 per cent, of the length of the bridge; in H. tumidus, only about 77 per cent. 

 The pectoral scute of//, majusculus is broader than that of H. tumidus, and the anal notch 

 is deeper. 



From H. corsoni, of the Bridger beds, the Uinta species appears to differ in several respects. 

 The peripherals over the bridges are evidently higher, the height in the former species amount- 

 ing to considerably less than one-half of the width of the bridge, while in the Uinta species the 

 height is equal to one-half of the bridge. In H. corsoni, from the inguinal buttress a broad 

 ridge runs backward to the rear of the hinder lobe at the midline. Mesiad of this, the upper 

 side of the plastron is concave, especially next to the ridge. Outside of the ridge the surface is 

 beveled off, near the buttress steeply, but less and less so more posteriorly, until on the pos- 

 terior outer angle of the xiphiplastron the slope is very gentle. In H. lumidus this ridge is 

 almost wholly obsolete and the upper surface of the posterior lobe is convex to near the border, 

 then pitches off nearly perpendicularly. This condition continues to the notch for the anal 

 sulcus. The hinder extremity of the xiphiplastron of H. corsoni is thinned off to a sharp edge 

 while in H. tumidus it is thick and the free edge is rounded off. 



Hadrianus? schucherti Hay. 

 Text-fig. 481. 



Hadrianus schucherti, HAY, Proc. U. S. Nat. Mus., xxn, 1899, p. 22, plates iv, v; Bibliog. and Cat. 

 Foss. Vert. N. A., 1903, p. 450. SCHUCHERT, Proc. U. S. Nat. Mus., xxm, 1900, p. 328. 



The present species is assigned provisionally to the genus Hadrianus, altho it belongs 

 possibly to Testudo. If really a Testudo, it is one of the oldest, if not the oldest of the genus, 

 coming as it does from the Upper Eocene. 



The type and only known specimen belongs to the U. S. National Museum. It was dis- 

 covered by Prof. Charles Schuchert, then of the U. S. Geological Survey, in the Zeuglodon 

 beds of the Jackson formation, near Cocoa post-office, in Choctaw County, Alabama. In the 

 immediate vicinity Professor Schuchert found bones of the mammals Basilosaurus, Dorudon, 

 and of the snake Pterosphenus schucherti Lucas. 



The upper portion of the carapace of this specimen had been eroded away down to the 

 upper borders of the peripheral bones. We are therefore unable to determine the characters 

 of the neural and costal bones. Nor are we able to determine whether the supracaudal scute 

 was single or double. 



The total length of the carapace was originally close to 750 mm. Its width is 525 mm. As 

 will be seen from an inspection of fig. 481, the lateral borders of the shell are nearly straight 

 and parallel with each other. In front of the axillary notch the margins round rapidly into the 

 anterior border. The shell is quite truncated in front. The hinder border approaches in form 

 a segment of a circle. Neither the anterior nor the posterior border is to any degree serrated. 

 The peripherals rise on the sides of the shell to a height of 100 mm. The passage of the lower 

 surface of the shell to the upper is quite abrupt; but this appears to be due to a considerable 

 extent to distortion by pressure. 



The borders of the carapace over the opening for the hinder limbs are flared gently upward; 

 over the openings for the forelimbs they are more strongly flared. 



The plastron is concave, a condition that indicates a male individual. It has a length of 

 675 mm. The anterior lobe has a length of 202 mm. and a width of 309 mm. The epiplastral 



