236 DE. A. S. WOODWARD ON THE [Apr. 18, 



the side. The neural canal in transverse section is somewhat 

 deepei- than broad. The neural spines are laterally compiei-sed, 

 thinnest at their front rugose border, and hollowed at the apex ; 

 they bear no lateral lidges, but their postero-lateral edges are pro- 

 duced into a pair of laminfe, which gradually expand downwards 

 into the posteiior zygapophyses. The next caudal vertebra in the 

 same specimen is probably the fourth, and is comparatively well 

 preserved with its neural spine complete (text-fig. 41, p. 235). The 

 centrum is concave in front, but flattened or even slightly convex 

 behind ; and it is much constricted between the prominent rims 

 of its two faces, without any trace of lateral pits. It is slightly 

 broader than deep, and the transverse processes (incomplete in the 

 fossil) arise within the upper half. Each lower border is im- 

 pressed by a facette for the chevron-bone, the hinder being larger 

 than the anterior impression. The neural arch is very massive, 

 and the nem^al canal is still somewhat deeper than wide. The 

 bases of the anterior zygapophyses {az.) prove them to have been 

 very stout ; and a thin vertical lamina or lateral flange of bone 

 extends downwards from the level of these zygapophyses to the 

 transverse processes on the centrum. The neural spine is massive 

 and placed above the hinder half of the centrum, slightly curved 

 backwards but scarcely overlapping the next vertebra ; it is 

 laterally compressed, thinnest at its front rugose border, and 

 somewhat hollowed and roughened at its truncated upper end. 

 There is a slight oblique ridge extending upwards and backwards 

 from the anterior zygapophysis on each side but soon dis- 

 appearing; and the posterior lateral edges of the spine are 

 produced into rather stout laminte which would originally ter- 

 minate below in the posterior zygapophyses. These zygapophyses 

 evidently converged below into a short mediaii ridge or zygosphene, 

 which fitted into the zyganti-um between the anterior zygapophyses 

 of the succeeding vei'tebra. In this next vertebra part of the 

 bony lamina aboA^e the transverse process on the left side is well 

 preserved, while the oblique ridge above the anterior zygapophysis 

 is comparatively strong. 



The four associated anterior caudal vertebrse of another spe- 

 cimen (Brit. Mus. no. R. 1984) are also very short and broad, with 

 deeply concave anterior face and nearly flat posterior face. The 

 largest closely lesembles the anterior cavidals just described, and 

 exhibits part of the lateral flange of bone which extends upwards 

 from the transverse process to the level of the zygapophyses. The 

 others are evidently intermediate between the most anterior and 

 the middle caudals, and one of them is represented in text-fig. 42, 

 p. 237. This specimen shows the comj)lete length of the transverse 

 processes. It has a less elevated neural aich than the vertebrae 

 already described, and exhibits the lateral bony flange above the 

 transverse process reduced to a slight i-ounded ridge. 



Apart from the specimens just mentioned, the few veiiebrfe 

 intermediate between the most anterioi' caudals and the middle 

 caudals are unknown ; but the latter are represented by a fine 



