CH DKISTODEEA. 1 07 



Champsosaueus australis Cope. 



American Naturalist, 1861, p. 670 (July). 

 Plate XXIIIlj; figs. 1-4. 



Eleven vertebrse, probably ofone individual, were found by Mr. Baldwin, 

 mingled with jaw fragments, with teeth of the Eocene Mammal Catathlceus 

 rhabdodon. All the pieces are enclosed in the black ferruginous matrix, in 

 which the mammalia of the Puerco epoch are found embedded. 



The vertebrae, are of about the same size and form, and all belong to 

 the dorsal series. Thej^ are characterized by their large width as compared 

 with their depth, differing in this respect from all of the known species. 

 The centra are regularly rounded below, and the borders are scarcely at all 

 flared. One of the dorsals, probably an anterior one, has a prominent 

 angular keel in the middle line below. The outline of the articular faces 

 for the neural arches is pyriform, the wide portion concave, with its external 

 edge decurved, and on the anterior half of the side of the centrum. The 

 decurvature is sometimes sufficient to resemble part of a rib-facet. Articular 

 faces of centra nearly plane. Sides of centra very little concave, a shallow 

 fossa below the base of each diapophysis. Non-articular surfaces of centrum 

 marked with a delicate thread-like sculjjture. and there is no coarse sculpture 

 near the edges of the articular surfaces. 



Diameters of keeled dorsal centrum: anteroposterior M. .012; vertical 

 .014; transverse .017. Diameters of a rounded dorsal: anteroposterior .013; 

 vertical .012; transverse .015. The dorsal vertebrte are wider and more 

 transverse than in either of the four known American species. They are 

 longer than those of the C. vaccinsulensis, and lack the marginal wrinkles of 

 the C. saponensis. From near Canyon Largo, San Juan River, New Mexico. 

 Champsosaurus puercensis Cope. 



Proceeds. American Philosoph. Society, 1881, Dec. p. lO.") (1882). Paleontological Bnlletin No. 34, 1882, 



p. 195, Feb. 20. 

 Plate XXIII ^3 ; figs. 5-10. 



This species is represented by a number of fragments, which include 

 three dorsal and four caudal vertebrae of apparently one individual. They 

 represent an animal of larger size than any of those heretofoi'e referred to 

 Champsosaurus, excepting the C. vaccinsulensis. In all of the vertebrse the 

 neural arch is more or less coossified with the centrum, and the animal had 

 probably reached its full size. 



