DINOSAUR EEOj\I THE ISLE OF WIGHT. 57 



terminates above the posterior zygapophyses. At the terminal 

 facet for the tubercle of the rib the width of the process is 

 about 3 centim. Inferiorly the transverse process is compressed 

 into a strong ridge, the base of which is rounded ; this ridge de- 

 scends posteriorly behind the facet, for the head of the rib to form 

 the anterior margin of the canal for the intervertebral nerve, while 

 at the free end of the process it expands to assist in forming the 

 transversely ovate tubercular articular facet. The anterior and 

 posterior inferior surfaces of the process are concave channels, 

 which deepen as they descend, the posterior enlarging into a con- 

 siderable excavation between the vertical buttress and the posterior 

 z) r gapophysis. The transverse width over the transverse processes, 

 as preserved, is about 17 or 18 centim. 



The base of the neural spine is about 9 centim. long. It is 

 broken away, but was compressed, widening posteriorly, where it 

 is about 1 centim. thick at the fracture. It there descends, widen- 

 ing in an A shape, with the lateral part concave ; and the flattened 

 posterior surface extends backward, to terminate inferiorly in the 

 ovate posterior zygapophysial facets, which are divided behind by a 

 slight concavity, which becomes narrower as it extends between 

 them inferiorly. The transverse width over the two facets is 

 5 centim. 



As is usual in dorsal vertebrae, the superior border of the centrum 

 is a little longer than the inferior border, indicating a slight arching 

 of the back. 



The 2nd vertebra differs chiefly in having the anterior articular 

 face flatter, and in having a more elevated ridge margining the 

 anterior border of the articulation for the head of the rib, while the 

 ridge below the transverse proeess is directed less backwards, and 

 more obviously curved. 



In the 4th the inferior ridge of the transverse process is nearly 

 transverse, and more obviously forms the posterior border for the 

 articular facet for the rib. 



In the 5th this ridge is inclined backward, and the posterior border 

 of the neural spine is rounded. 



The 6th and last vertebra of the series is a little crushed, so that 

 the inferior basal ridge appears to be either obliterated or less deve- 

 loped. The base of the neural arch below the transverse process 

 has now become a somewhat compressed area, rounding anteriorly 

 into the pedicle of the neural arch, slightly concave in the middle, and 

 margined posteriorly by the broad flattened rounded ridge descending 

 from the transverse process. Behind this ridge is a deep impression 

 like a thumb-mark on plastic substance. The tubercle for the rib 

 has now ascended so as to be quite on a level with, or rather above 

 the transverse process, and immediately in front of it ; and it has 

 beeome smaller. It is wider than deep ; and the measurements are 

 -between two and three centim. Its superior surface is convex ; 

 and the convexity extends inward towards the neural spine. The 

 greater part of it rises above the level of the zygapophysial facet, 



