780 THE WHITE RIVER FAUNA. 



The dorsal vertebrae have transversely-oval articular faces, and centra 

 without inferior keel or ridge. The vertebrae are all dorsal, hence the 

 diapophyses have the usual form in the order for costal articulation, and 

 do not project as far inferiorly as the plane of the lower face of the. centrum. 

 It does not project beyond the anterior zygapophysis, and the lower half is 

 especially developed as the costal condyle. The sides are separated from 

 the wide, flat, inferior surface by an obtuse angle. Neural spine a keel 

 extending from the front of the arch and rising into a short obtuse apex 

 above the articular ball. There is a collar round the ball, which is faintly 

 visible on the inferior side. 



Measurements. 



M. 



Length of centruni COIMO 



Width of cup 0018 



Depth of cup 0010 



Elevation of neural arch anteriorly 0015 



Elevation of neural spine and arch posteriorly 0043 



Total expanse in front 0047 



The dorsals represent several individuals. 

 Horse Tail Creek, Northeastern Colorado. 



CREMASTOSAURUS Cope. 



Synopsis New Vertebrata, Colorado, 1873, p. 18. Annual Report U. S. Geol. Surv. Terrs., 1873 (1874), 



p. 515. 



This genus was proposed for a lizard which presents some peculiar 

 characters of the cervical vertebrae. There are five of these preserved in a 

 continuous series. They are quite robust and short, resembling somewhat 

 those of the Phrynosoma cornutum in proportions, but have remarkably small 

 articular ball and socket as compared with that species. Another marked 

 feature is the rib-like hypapophysis, which is equally developed on the fifth 

 as on the second vertebra, being bounded by a fossa or groove on each side. 

 It is probably continued, but less distinctly, on the dorsal vertebrae. 



The neural arch is capacious in the cervical region, and each neura- 

 pophysis is excavated below the posterior zygapophysis, and sending a ridge 

 downward and backward around the centrum, continuing as a low shoulder 

 on the inferior face. Diapophysis with a single narrow capitular articula- 

 tion, extending obliquely downward and forward; that of the third vertebra 



