AND AVES OF NORTH AMERICA. 



221 



l. 



Lin. 



3 



0.5 



1 



0. 



1 



1.5 



8 



0.5 





10.5 





!) 





4.5 





15. 





S5 



In 



Length <>(' centrum below, 

 Width of oup, 

 Depth " " 



Width between extremities diapophysis, 

 Depth articular face diapophyses, 

 Prom diapoph. to end zygapophysis, 

 Between zygosphen and zygapophysis, 

 Width centrum anterior to ball, 

 " of neural canal behind, 



This vertebra indicates a, formidable snake-like animal, which paddled and sculled in the Cretaceous Ocean, or 

 perhaps wandered more or loss on land. Its length by comparison with the C. propython was probably thirty 

 feet. 



Prom the lower bed of Cretaceous Green Sand at Swedesboro, N. J. Discovered by Professor O. C. Marsh, of 

 Yale College. 



CLIDASTES INTERMEDINS, Lcidy. 



Proceed. Acad. Nat. Sci., January, 1870. 



This species is established on several cervical and dorsal vertebras, with portions of mandibular rami and other 

 bones, from Alabama, discovered by Dr Nott, of Mobile. 



They indicate a species intermediate in size between the two others here described. The dorsal vertebras are 

 rather slender, more so than in C. iguanavus, and with articular faces with cup and hall remarkably oblique to the 

 axis of the vertebra. The dense layer of the bone is thrown into numerous rugosities and ridges, as in 0. 

 propython. 



What is more characteristic, is the robust and even swollen form of the crowns of the teeth, and their slightly 

 rugose enamel for the basal three-fourths the height. There are no facets. 



Rotten Limestone Upper cretaceous, of Pickens Co., Alabama, 



-. ' 



CLIDASTES PROPYTHON, Cope. 



Post. Society, Nat. Hist, Proceedings, 1800, p. 258. 



This species is known from an almost complete skeleton, found by Dr. Edward R. Showalter, in the Rotten Lime- 

 stown, near Uniontown in Alabama. 



Its general proportions may be estimated as follows. As a considerable number of vertebra has been lost, it will 

 be necessary to illustrate it in some points from Cuvier's estimate of the length of Mosasaurus giganteus. 



M. giganteus. 

 2 

 11 



5 



Atlas and Axis 

 Corvicals with liypapophysis, 

 Dorsals with zygapophyses and 



ribs, 

 At least to be added to this 

 series, 



18 

 84 

 51 



188 



1 Total 



2 Between the last and those 



bearing chevron bones, (estimated 

 for C. propython), 



3 Caudal s with chevron bones, 



Total, 



C. propython. 



2 



6 



15 

 10 



m 



06 

 60 



189 



AMERICA. 1'IIILO. SOC. — VOL. XIV. 50. 



