582 BRITISH FOSSIL REPTILES. 



the ' tubercle ' and that for the ' head ' of the rib is ten inches, which indicates the extent 

 of the ' neck ' of the rib at this fore part of the thorax. The neural spine is strengthened 

 by lateral buttress-like ridges rising from the neural platform ; it is of a massive 

 quadrate form and seems to have terminated obtusely. The zygapophyses are supported 

 by buttress-like vertical ridges.* All the characters of this massive vertebra bespeak the 

 great strength of the back-bone of the enormous saurian. The total vertical extent of 

 the above vertebra, which is incomplete at the wider part of the centrum, is 2 feet 

 4 inches ; the breadth at the diapophyses is 1 foot 6 inches. 



The vertebra which is the subject of ' Binosauria,' PI. 76, from a hinder position of the 

 trunk than the above-described, exemplifies the cetiosaurian characters of texture (fig. 2, p) 

 also of a contracted antero-posterior extent of the neural arch as it rises from the centrum,! 

 and of a partial subsidence of the anterior ball. This vertebra has been crushed and fractured; 

 the right side is pressed obliquely backward for an inch or so beyond the left side, so that 

 the length of the centrum, measured as it has been squeezed out of shape, exaggerates its 

 original or natural longitudinal diameter. This would not exceed, according to my estimate 

 eight inches. The vertical diameter of the centrum has also been pressed down beyond its 

 original extent. I estimate the ball or fore part at 6^ inches, the cup behind at 7 inches, 

 in height. The neural arch, as in the type-vertebrse of Cetiosaurus lonc/iis,X is retained in 

 anchylosed union with the centrum to the extent shown in Plate 76, viz., eight inches. 



A vertically grooved median ridge appears to commence at the back part of the base 

 of the spine. This process is wanting ; it probably would have added a foot to the 

 present vertical extent of the vertebra, which is sixteen inches. Minor projecting parts 

 have been equally broken away, and, as usual, lost in the quarrying or extricating 

 operations. Such fractures occur on both sides of the prominent rim of the hinder cup 

 of the centrum (as at p, fig. 2, Pi. 76). The singularly naturally compressed upper 

 and middle part of the centrum (ib. /) imderlying the neural canal and forming a 

 vertical plate or medial wall of bone, three to four inches in height, and but six lines to 

 eight lines in thickness, has been in part broken away, exposing that canal. The fore 

 and hind outlets of the neural canal are squeezed into a narrow, vertically lengthened, 

 oval shape (ib., fig. 2, «). 



The neurapophysis rises by two buttress-like columns (ib., fig. \, n n, n) which converge 

 as they ascend and overarch the lateral depression / . The base of the neural arch is 

 coextensive with the centrum, save in so far as the anterior ball may have projected 



* "On Cetiosaurus from Oolitic Formations," ' Proc. Geol. Soc.,' 1841, 1. c, p. 459. Cetiosaurus 

 lonyus is defined as in the ' Report,' and distinguished from the Cetiosaurus brevis of the Wealden Forma- 

 tions, pp. 101, 102, which will probably prove to be referable to a distinct cetiosauroid genus. 



t In the account, illustrated by woodcuts, given by Phillips in his excellent ' Geology of Oxford,' 

 pp. 246 — 294, a vertebra, supposed to be lumbar, the subject of the diagram Isxsviii, p. 257, has assigned 

 to it the following admeasurement: — "Greatest length from front to back (crushed) 46 in." I have 

 found no trunk-vertebrae of the Cetiosaurus from the Kirtlington Oolite sn short as this. 



X " In all these vertebrae the neurapophyses are anchylosed to the centrum," Ac— ' Report,' p. 102. 



