96 



Tkionyx vagan.s Cope. 



Bulletin of tlic United States Geological Survey of the Tenitories, No. 3, 1874. — Trionyx ? forentus, Leidy, 

 Proceeding.s of the Academy of Natural Sciences, Philadelphia, 185G, p. 312. 



Represented by a number of fragments of costal bones, and, perhaps, of 

 sternals, also. The former are rather light or thin for their width, and are 

 marked with a honeycomb-pattern of sculpture, in which the ridges are thin 

 and much narrower than the intervening pits. They incline to longitudinal 

 confluence at and near the lateral sutures. Several areae are not unfrequently 

 confluent in a transverse direction near the middle of the bone. 



Measurements. 



M. 



Width of the costal bone 0.0370 



Thickness of the costal bono 0. 0045 



Number of area; in 0'".019, 4 and r>. 



This species differs from the T. foveafus, Leidy, in the much narrower 

 interareolar ridges and larger areae, and in their longitudinal confluence at 

 the margins, characters exhibited by munerous specimens. 



Lignite Cretaceous of Colorado; near the mouth of the Big Horn River, 



Montana; Long Lake, " Nebraska;'' found at the last two localities by Dr. 



Hayden. 



CYNOCERCUS, Cope. 



Established on a metapodial bone and caudal vertebrae of a tortoise of 

 uncertain, but in any case peculiar, aftiiiities. The caudal vertebrae are not 

 anterior ones, almost lacking diapophyses, but are long and slender, and the 

 articular faces singularly incised. The form had a tail more elongate than 

 the snapping-tortoise, and different from it in details of composition, especially 

 in l)eing of the procoelian type. 



Associated with the remains of CUdastes, and other saurians, and at a 

 distance of two or three Iiundred yards from the locality of the fossil Proto- 

 stega gigas, were found some vertelirse of a Testudinate reptile, which ap- 

 proaches the type of Trionyx. 



Cynocercus incisus Cope. 



The vertebrae have elongate centra concave below, and have well-devel- 

 oped diapophyses. One vertebra has transversely oval articular extremi- 

 ties; in another, they are much less depressed. The former is the more an- 



