764 THE WHITE EIVER FAUNA. 



specimens are unfortunately broken in every instance, so that the question 

 of notches or mucros cannot be decided. The costal bones are moderately 

 thick, and alternate in width, narrower and wider. The dermal sutures do 

 not display raised margins. The anal marginal bone is wedge-shaped, with 

 the posterior margin representing a truncate apex. Its surface and margin 

 are convex, and the anterior sutural margin is concave. 



A fragment, which is in all probability the posterior lobe of the plas- 

 tron, is characteristic. It is thick, and its inferior face is somewhat recurved 

 posteriorly. The outline of the margin presents a pronounced obtuse angle, 

 and the edge is several times abi'uptly notched. 



Measurements of No. 1. 



M. 



( at base 1^"^"'=='^ "^^^ 



Diameters of half of lip i ( transverse 043 



( length outer edge 056 



Diameters second marginal from anal < 



^ < width 030 



Length free margin of anal 026 



Width of anal above 050 



Thickness of a vertebral bone .011 



Thickness of a costal at middle 009 



Found by myself near the head of Horse Tail Creek, in Northeastern 



Colorado. 



Testudo QUMiRATUs Cope. 



Plate LXI; fig. 5. 



This tortoise was, perhaps, the largest of those of the White River 

 beds. It is, unfortunately, only represented so far in my collection by the 

 lip of the plastron and by an imperfect marginal bone. The former frag- 

 ment indicates clearly a species quite unlike the others here described. 



The lip is thick at the base, and the superior surface descends gradu- 

 ally to both anterior and lateral edges. The middle of the former is notched, 

 but there are no other indentations of importance. The lateral borders do 

 not converge, as in T. laticimeus, but rather diverge, as in Hadrianus octo- 

 narius. Its form is more like that of T. Ugonius than any other species, but 

 it differs- from it and from all other species known to me in the absolutely 

 transverse posterior gular suture. The suture follows an angular groove, 

 which cuts the lip off from the inferior surface of the plastron, which lies 

 behind it. The latter swells prominently behind the suture, but less so at 



