G30 GEOLOGICAL SURVEY OF THE TERKITOKIES. 



sosternal bone truncates the clavicular extensively, giving it thus a more 

 elongate form. The gular scuta expands to its front margin. The mar- 

 ginal bone is stout and sharp-edged, and is not so deeply impressed by 

 the dermal suture as in P. pohjeypha. 



Emys polycyphus, Cope. 



Pcdwotheea pohjcijplia, Coi)e. Pioceecl. Amer. Pbilos. Soc, 1872, p. 463. 



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 

 animal. The deeply-impressed scutal sutures, and heavy iiroportions, 

 as well as the elevated carina of the carapace, indicate affinity witij 

 Cistudo, or, perhaps, Tcstudo. As another generic character, it may be 

 noted that the vertebral bones are subquadrate and support the neura! 

 canal without intervening lamina. 



The carina ot the carapace is abruptly interrupted occasionally ; some- 

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

 marginal bones are well recurved, and the scutal sutures are deeply im- 

 pressed on them. 



Measurements. 



• M. 



Length of vertebral boue 0(19 



Width of vertebral boiie OUlvj 



Leuo;tli of uiarifinal bone 01 



o^ 



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



o^ 



HADRIA^^US, Cope. 



Proceed. Amer. Philos. Soc, 1S72, p. 408. 

 This genus resembles Tcstudo in form, but has two anal scuta, as in 

 moat Umydidw. The claws are short and stout: an ungual phalange is a 

 long oval viewed from above, and is oval in section, with obtuse edges. 

 The articular surface is subinferior. A cervical vertebra is of moderate 

 length, and has a very prominent anterior zygapophysis. The centrum 

 presents two distinct convex articular surfaces auteriorlj', and one trans- 

 verse one behind. A sacral is free from the carapace above; it presents 

 two subround articular cups posteriorly and outwardly ; the anterior 

 are broken off. These characters are observed in a large specimeu of 

 M. Corsonii. 



Hadrianus allabiatus, Cope. 



Proceed. Amer. Philos. Soc, 1872, p. 471. 



This large land-tortoise is nearer in general form to the IT. corsonii 

 than to the H, oetonarius, but differs from both in the absence of the pro- 

 jecting lip of the anterior lobe of the plastron, which is thus simply 

 truncate. The mesosternum is not cordate, but has much the shape of 

 that of S. corsonii, that is, rhombic. The scutal sutures are deeply 

 impressed. The plastron is strongly concave. Carapace without irreg- 

 ularities of the surface. Length 18 inches. 



From the Bad Lands of Cottonwood Creek, Wyoming. 



Hadrianus octonarius, Cope. 



Proceed. Amer. Philos. Soc, 1872, p. 4G8. 



The IT. octonarius is distinguished from its congener in many ways. 

 It is of elongate form, strongly contracted at the bridges, but expanded 



