| OCR Text |
Show 234 DR. A. S. WOODWARD ON THE [Apr. 18, anterior vertebra is deeply opisthocoelous, and the anterior two-tliirds of the upper half of its lateral face are impressed 011 each side with a shallow ovoid cavity, which has a gently rounded (not sharp-edged) margin. The centrum supposed to represent a middle dorsal vertebra is slightly smaller, and the ovoid depression in the upper half of its lateral face is more extended antero-posteriorly. Neither specimen exhibits any hollowing of the lower face. A posterior dorsal vertebra, which seems to be the last and in direct contact with the sacrum, is represented not only by its centrum but also by the greater part of the neural arcli text-fig. 40). It is remarkably shortened, the centrum being still Text-fig. 40. Cetiosaurus leedsi.- Posterior dorsal vertebra, lacking neural spine; posterior and (A) right lateral aspects, zs., zygosphene. About g nat. size. about as wide as deep, but its length somewhat less than half the extreme diameter. This centrum is much constricted, and the shallow depression in the upper part of its lateral face disappears at the base of the neural arcli. Its anterior face is not well preserved, but seems to have been slightly convex; while its posterior face is only gently and irregularly hollowed, as if it had been originally capped by cartilage. The neural canal is ovoid in section, and much deeper than wide. The deep and laterally-compressed zygosphene (zs.) is prominent. An isolated neural spine, which probably belongs to a dorsal vertebra, is laterally compressed and short, with a truncated and somewhat hollowed apex; there are no bony laminae or ridges on its lateral face, but a pair of laminae extend down its postero lateral edges and expand below into the prominent triangular zygapopliyses. |
