644 



PROF. "B. g. seelet on the eeptile 



to a level with the centrum, and are thick strong processes which 

 have the articular faces somewhat rounded and convex, as though 

 to allow of considerable play. Behind the facets the bone is a good 

 deal compressed, so as to be concave in length and concave from side 

 to side. The base of the neural spine, as preserved, is a square 

 pillar, rather more than ^ inch in diameter, which appears to rise 

 vertically. In front of this and between the transverse processes is 

 a deep excavation about | inch long and wide. The neural canal is 

 large, and formed almost entirely by the neural arch, the neura- 

 pophyses converging so as to almost unite in the middle line of the 

 base of the neural canal. The width of the neural canal is greatest in 

 front, where it is -fy inch ; and its height is greatest behind, where 

 it is about the same, or a little more, the canal being depressed in 

 front and compressed posteriorly, the width of the canal behind 

 being ^ inch. The height from the base of the centrum to the 

 upper surface of the posterior zygapophyses is 3^ inch ; the width 

 over the outer margins of the posterior zygapophyses is 1 T 7 ^ inch ; 

 the length, from posterior to anterior zygapophyses is 3-^- inch ; the 

 width over the anterior zygapophyses was about 2-^ inch. 



Dorsal Vertebrce. 

 (See Mnzel, pi. ii. figs. 1-3, pi. vii. fig. 24.) 



Of the two dorsal vertebrae the more anterior has the lower half 

 of the centrum badly preserved, but shows the anterior zygapo- 

 physis, transverse process, and neural , spine completely. In this 

 the transverse processes extend more horizontally outward, while in 

 the later vertebra they are directed more obliquely upward. To begin 

 with the latter (PI. XXX. fig. 3), the centrum is 2^ inches long, and 

 has the anterior face subquadrate, inches deep, and 2 T L- wide. It 

 is moderately concave. The posterior face is badly preserved at the 

 margin, but appears to have been much smaller, since it is inch 

 deep, and, as preserved, is rather wider. It has a deep pit just below 

 the neural canal, while the remainder of the face is convex from above 

 downward, slightly convex from side to side, and smooth. The 

 neural canal is 2 inches long. The base of the centrum is flattened, 

 margined by rounded lateral ridges. The upper parts of the sides of 

 the centrum are concavely compressed, as though squeezed with the 

 finger and thumb ; and here, in the middle of the centrum, the trans- 

 verse measurement is 1 inch a little below the' neural canal. The neural 

 arch is lofty, the height to the origin of the transverse process from the 

 base of the centrum being 3^ inches, and from its base 2 T 2 Ij inches. 

 The buttress which supports the transverse process is flattened at 

 the side, since it is formed by pillars which arise from the anterior 

 and posterior margins of the centrum, and converge as they ascend 

 so as to form a sharp angular ridge beneath the transverse process, 

 which is flattened and expanded above. There is a deep excavation 

 in front of the vertical A-shaped masses which support the trans- 

 verse processes ; and these were placed behind the anterior zyga- 

 pophyses. There are much larger but similar posterior excavations, 

 which are subtriangular and in front of the posterior zygapophyses, 



