Nodosaurus textilis Marsh. 109 



side is still to be seen in the matrix, and from it that of 

 the right has been restored. The centrum is roughly 

 cylindrical and the length is somewhat less than its 

 greatest diameter. Ventrally it is- characterized by a 

 shallow longitudinal groove which Marsh mentions in his 

 original description, and there is evidence of at least one 

 chevron facet at its posterior end. Laterally there is 

 no trace of pleurocoele, and the diapophysis arises from 

 a little above the middle of the bone. The diapophysis 

 is light, and curves somewhat toward the rear. Below 

 the diapophysis, the surface of the centrum is somewhat 

 concave, with evidence of a faintly impressed vertical 

 groove. The anterior -face is practically plane, the 

 posterior slightly concave. 



The pedicels are of considerable antero-posterior 

 length, which somewhat exceeds half the length of the 

 centrum. The pedicels are simple, being unsupported 

 by buttresses or laminae. The spinous process is thin 

 but expanded fore and aft, so that its total length is 

 nearly as great as is that of the entire centrum. The 

 summit merges into a layer of irregular dermal bones 

 which extend in a horizontal manner from the left side ; 

 on the right they are not preserved. The zygapophyses 

 are simple, those in front looking inward and upward, 

 while those in the rear look downward and outward. A 

 slight fore-and-aft lamina — horizontal lamina — connects 

 the zygapophyses on either side mth each other; above 

 these the face of the spinous process is for the most part 

 concave. The neural canal is oval in section, ^vith the 

 apex uppermost, and is of considerable size, as the 

 measurements show. The ventral median groove and 

 the character of the low spinous process are the most 

 distinctive features of this bone. 



Caudals 9 and 10 (fig. 3). — These were in contact in 

 the matrix and except for their processes are very well 

 preserved. No. 10 is a little the wider. The anterior 

 face of the centrum shows a slight dorso-ventral 

 convexity, and the posterior face is correspondingly but 

 somewhat more markedly concave. Transversely, each 

 face is flat. The ventral groove is apparently deeper 

 than in caudal 4 and the posterior chevron facets are 

 especially marked. The better preservation of the bone 

 surface leads to the supposition that these and other 

 distinctions from caudal 4 are more apparent than real. 

 The diapophyses are not preserved, but their bases are 



