TESTUDINATA. 765 



the middle line than laterally. The marginal is probably the nuchal, and 

 displays a part of the nuchal scute. The latter was at least not very narrow, 

 and its free edge is concave. The borders of the dermal grooves are raised. 



Measurements. 



M. 



Length of lip from gular groove 070 



Width at base ■. 120 



Thickness at base 02i> 



Length of nuchal scute 041 



Head of Horse Tail Creek, Northeastern Colorado. 

 Testudo laticuneus Cope. 



Faleoatological Bulletin No. 15, p. 6, August 20, 18T3. Annual Report U. S. Geol. Surv. Terrs., 1873 



(1874), p. 511. 

 Plate LXI; fig. 1. 



A number of fine chelonites which I obtained during my expedition of 

 1873 are, unfortunately, not accessible for description at present. Among 

 these will probably be found some of the specimens of this tortoise, to which 

 my original description refers. One individual, in a good state of preserva- 

 tion, must serve as the basis of the present description. It is, however, one 

 of the, best which I procured, although a little distorted in some places by 

 pressure. 



The general form is broad and depressed. The anterior and posterior 

 outlines of the carapace are subtransverse, the former being nearly straight 

 and the latter a little convex. The lip of the plastron projects much beyond 

 the anterior border of the carapace, while the posterior lobe is included 

 within that of the carapace. The free marginal bones ai-e straight, but few 

 of them being a little concave on their superior face. The anal bone is 

 truncate wedge-shaped, with the free edge and the general surface gently 

 convex. When the dermal scutal sutures reach the margin, there is a short 

 acute mucro on both anterior and posterior marginal bones. There are na 

 keels -nor tuberosities on the carapace. 



The plastron is rather flat, indicating a female animal. The anterior 

 lip is large, and each half is rather longer than it is wide at the base of the 

 external side. The exterior borders converge anteriorly, leaving a short 

 margin, which presents six strong teeth, three on each half, of which the 

 adjacent median ones are the widest. The posterior lobe is divided by a. 



