G4 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Dec. 3, 



the uppermost angle of the octagon occupied by the excavated floor of 

 the neural canal. The short sides of the vertebral body are concave 

 from before backwards, and in other specimens exhibit a slightly 

 rugose marking. 



The neural arch is very small in proportion to the size of the body 

 of the vertebra, and its contour is nearly that of an equilateral tri- 

 angle with a curved base. 



The very stout sides of the neural arch are continued upwards 

 into a strong spinous process, which is broken off a short distance 

 above its origin and nearly on a level with the upper parts of the 

 zygapophyses. Of the latter the posterior pair are turned towards 

 the eye, and are much broken. The hinder face of the right anterior 

 zygapophysis is visible (at d), and its curved contour is nearly entire. 



The transverse process of the right side (the only one preserved) 

 springs by a long line of origin from the lower part of the neural arch 

 and from the upper half of the circumference of the vertebral body. 

 It is greatly flattened from before backwards, and its lower half (c) 

 ends, at a distance nearly equal to half the diameter of the body of 

 the vertebra, in a rounded edge, which appears to be complete and 

 unbroken. The upper half, on the other hand, terminates in an ob- 

 viously rough and fractured extremity. I conclude from this circum- 

 stance, and from the characters exhibited by the proximal ends of the 

 ribs, which I shall immediately describe, that the upper division of 

 the transverse process extended much further outward than the lower, 

 and I have indicated this in the dotted restoration of the left side 

 of the vertebra. 



inch. 



Height of body of vertebra 1*6 



Transverse diameter 1*6 



Length 0-47 



Height of neural arch 0*3 



Depth of transverse process 0-8 



Thickness of transverse process 0-2 



The best-preserved rib is 6j inches long* and half an inch broad, 

 measured in a direction perpendicular to its length. It is, however, 

 much flattened from before backwards, so that its thickness does not 

 amount to more than one-sixth of an inch. The face of the rib is 

 not flat, but it is somewhat excavated, so that the bone is thinner 

 in the middle than at the edges. At its proximal end the rib 

 exhibits a very distinct tuberculum and capitulum. The former 

 projects, so as to disturb the sweep of the curve of the convex 

 side of the rib and to convert it for a short distance into a 

 concavity, and it is abruptly truncated posteriorly. The capitulum 

 of the rib continues the line of its general curvature for half 

 an inch beyond the tuberculum, and ends in a rounded ex- 

 tremity. I presume that the capitulum articulated with the lower 

 half of the transverse process (c), and that the tuberculum articu- 



* The sternal end of the rib is broken off. It was certainly much longer when 

 perfect, as the rib from Lord Enniskillen's collection, though more slender, 

 measures 8? inches along its curve, and still presents a fractured extremity. 



