232 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxvi. 



looking outward and downward. From a posterior view, both verte- 

 brae show, just above the neural canal, a median pit which extends 

 forward and downward into the arch. 



The second dorsal. — This vertebra differs from the preceding 

 chiefly by the development of a higher spinous process, more robust 

 transverse processes, greater length of centrum, and more elevated 

 position of the capitular facets on the lateral surface of the neura- 

 pophyses. The distal extremity of the centrum is not so deeply 

 cupped as in the preceding vertebra, and the anterior extremity is 

 nearly plane, being only slightly concave dorso-ventrally. In median 

 cross section the centrum would be wedge-shaped. The subcircular 

 neural canal is more reduced, and the tubercular rib facet looks 

 downward and forward. 



The third dorsal. — The third dorsal (see fig. 15) may be distin- 

 guislied from the second by the increased size of the tubercular and 



1 2 



p-^yg 



Pig. 15. — (1) Third doksal vertebra of CAMrxosAURrs browni. IIolottpe. Cat. No. 

 4282, U.S.N.M. ; \ xat. .size, .side view: (2) anterior view ok same; a. zyp, prezyga- 

 I'orHY.sEs : (/, DiAPOPiiYSEs ; ij. parapophyse.s : /). ~//r/, postzvgapophyses ; ,9, neural 

 spine; s', neuro-central suture. 



capitular facets, and the more elevated position of the latter. Also 

 by the more rounded ventral surface of the centrum, which slightly 

 exceeds the second in length. 



Dorsals fovr to fourteen. — The succeeding vertebra^ are so similar 

 in most respects that they may best be described together. The cen- 

 tra, allowing for distortion by crushing, gradually increase in length 

 from the first to the twelfth, which is the longest of the series in No. 

 4282. They have their articular extremities concave, more especially 

 on the posterior end, but to a le&s degree than in those vertebra3 an- 

 terior. The depressions so marked in the sides of the cervical and 

 anterior dorsal regions below the neuro-central suture, decrease in 

 approaching the trunk, and from the fourth dorsal to the loins the 

 sides are approximately fiat vertically, though concave longitudinally, 

 caused by the expansion of the ends of the centra. There is also a 

 diminished angularity of the keel so that the vertebrae of the mid- 



