xi. MEGALOSA UR US VERTEBRA. 201 



The dimensions of this vertebra are as follows : 



Length of corpus . . . . 2-00 inches above. 



. . . . 2 '35 below. 



Height of articular face . . . 2'2O ,, 



Breadth of ... 1-85 



It will be seen that the vertebrae of the two teleosaurians on 

 the same diagram are longer and more cylindrical. 



The anterior dorsal vertebrae of megalosaurus are known by 

 a fine example (probably fourth or fifth) in the Oxford Museum, 

 which was figured by Dr. Buckland (Geol. Trans., Second Series, 

 vol. i. 1824, plate XLII. fig. 2). This lithograph does not express 

 the zygomatic articulations, and some other points of the vertebra, 

 so well as the figure 3 in Diagram LIX., which is taken from the 

 same specimen, but it shews well the great middle contraction of 

 the corpus, and the expanded articular faces. The neural spine 

 is broken off ; its probable length is sketched in the diagram re- 

 ferred to. Professor Owen gives in his Monograph of Megalosaurus 

 (Palaeont. Soc. Memoirs, 1855) a finished representation of a series 

 of anterior dorsals resembling ours from the Wealden, in which the 

 spinous processes referred to are fourteen inches long. 



The Oxford specimen measures 4/5 inches in the length of the 

 body, 4*15 inches from the neural canal to the lower edge of the 

 articular face, and 3-85 across the face, which thus appears a little 

 oval, and .higher than broad. The anterior face, though slightly 

 depressed in the middle, is generally convex, and very revolute 

 toward the lower edge. The posterior is more generally but not 

 deeply concave, and also revolute toward the lower edge. The body 

 is very smooth, and so much contracted in the middle in the lower 

 half as to resemble an hour-glass. Above this the upper part rises 

 and expands suddenly, so as to leave a deep longitudinal pit below 

 the suture, which rises to an arch in the middle. The hour-glass 

 or barrel part of the body is 2'5 inches in diameter ; the sides of 

 the pit are so pressed in as to be only 1-5 inches apart. The dia- 

 pophyses and parapophyses are broken, but their bases are traceable. 



The diapophysial ridge rises obliquely from the edge of the upper 

 part of the posterior face, and has a deep hollow on each side of it. 



The anterior zygapophysial process presents a spoon-shaped pro- 

 jection, hollow above and buttressed below, 'with an expanding 



