TESTUDINATA. 131 



I have not included the E. cihoUensis (Cope Report Expl. Surv. W. of 



100th Mer., Wheeler, iv, pt., ii, p. 57), as it may have been founded on a 



larger E. euthneta. 



Emys polycypha Cope. 



Annual Rejiort U. S. Geol. Surv. Terrs., Hayden, 1872, pp. 625, 630. Palaotheca polycypha Cope, Pjocecd. 



Amer. Philos. Soc, 1872, p. 463. 



Plate XVII, figs. 20-22. 



This species of tortoise is indicated by vertebral costal and marginal 

 bones of very small individuals. These bones are, however, not only 

 thoroughly ossified, but are very stout, indicating the adult age of the ani- 

 mal. The deeply impressed scutal sutures, and heavy proportions, as well as 

 the elevated carina of the carapace, indicate affinity with Cistudo or, perhaps 

 Testudo. As a generic character, it may be noted that the vertebral bones 

 are subquadrate, and support the neural canal without intervening lamina. 



The carina of the carapace is abruptly interrupted at intervals ; some- 

 times with, sometimes without, a pair of pits, one on each side. The marginal 

 bones are well secured and the scutal sutures are deeply impressed on them. 



Memurements. 



M. 



Length of vertebral bone 009 



Width of vertebral bone 0085 



Length of margiual bone 01 



This is the last of the tortoises of the Bridger formation. 

 Emys terrestkis Cope. 



Annual Report U. S. Geol. Surv. Terrs., Hayden, 1872, p. 629. PaUeotheca terrettrie, Cope, Proo. Amer. 



Philos. Soc, 1872, p. 464. 



Plate XVII, figs. 23-25. 



In this species and the following, the lip only is inclosed by the gular 

 scuta, which only reach the apex of the mesosternal. In neither are the 

 articulations of the bridge with the costals known. Represented by three 

 individuals, one of which may be regarded as the type. They are all 

 thinner than the P. polycypha, and larger, being about equal to the Aromo- 

 chelys odoratus of our ponds. 



In the type specimen the carina of the vertebral bones is interrupted 

 by a deep sutural groove, which is less pit-like than in P. polycypha. The 

 bone itself is broader than long, being perhaps, from the hinder part of the 



