784 THE WHITE EIVER FATOTA. 



riorly, as is the case with a dorsal of C. oregonensis. The hypapophysial 

 ridge is narrower, and is subacute in a dorsal vertebra. 



The zygapophses are well expanded, and the zygosphen is wider than 

 the cup. The superior and prominent portion of the rib articulation is 

 nan'ower than the inferior flat portion. 



Measurements. 



M. 



Length of centrum 0.0030 



Diameter of ball J t^^"^^^'^^ ^J,l 



( vertical 0016 



Width between parapophyses 0024 



Depth of entire vertebra .0045 



CALAMAGRAS Cope. 



Locu ciiatis, 1873, 1874. 



Neural spine small and obtuse ; no process below the prezygapoph- 

 ysis, nor longitudinal ridge of the centrum posterior to the rib articular 

 surfaces. The latter is undivided. Inferior median line with a keel, which 

 is probably produced into a hypapophysis on the anterior part of the col- 

 umns. 



This genus belongs most probably to the same natural division as 

 OgmopJiis and Aphelophis, which when fully known may prove to be the 

 existing family of Erycidoe. or Lichanuridce. Calamagras shares the charac- 

 ters of the two genera named, so as to stand between them in the natural 

 system. 



Calamagras murivorus Cope. 



New vertebrata from Colorado, 1873, p. 15. Annual Report U. S. Geol. Survey Terrs., 1873 ('74), p. 517. 



Calamagras truxalis Cope 1. c. 



Plate LVIIIa; figs. 13-15. 



Parts of three vertebral columns, including thirteen vertebrse, represent 

 this serpent. 



The zygosphene is a little wider than the articular cup. The ball, 

 viewed directly in the line of the axis of the centrum, has a wide, transversely 

 placed oval outline. The balls of a set of three vertebrse in which the 

 hypapophyses are best developed, and which I therefore supposed to 

 belong to the anterior part of the series, are more nearly round. The ridge 

 connecting the zygapophyses is deeply emarginate. In the anterior ver- 



