360 FOSSIL REPTILES. 



behind, on that of the vertebra which follows, and for this pur- 

 pose each of these apophyses has an horizontal prominence in 

 front which passes under that which precedes it. This arrange- 

 ment holds the place of articular apophyses. 



The annular parts grow narrower towards the tail; their 

 spinous apophyses diminish in all directions, and also their 

 articular laminae. 



There are no true transverse apophyses, but in a certain num- 

 ber of these vertebrae, the body has on each side two tubercles, 

 nearer its posterior than its anterior edge. The most elevated is 

 contiguous to the annular part, and convex. It is the only 

 vestige of transverse apophysis which is visible. It serves for 

 the articulation of the tubercle of the rib. The other is a little 

 lower and slightly concave. It receives the head of the rib. 

 According to the observation of Mr. Conybeare, verified by M. 

 Cuvier, this disposition of the lateral tubercles continues, from 

 the first, as far as the seventeenth or eighteenth. Afterwards, 

 the upper tubercle ceases to be contiguous to the annular part, 

 and approaches, by degrees, to the lower one. It has been 

 found still convex, though very much lowered, as far as the 

 thirty-fourth vertebra. 



These tubercles have been found distinct as far as the forty- 

 third vertebra, and very near the pelvis. They are then small, 

 and both concave. But here specific and even individual 

 variety must be taken into consideration ; for Mr. Conybeare 

 found them reduced to a single one at the fortieth vertebra in 

 one of his specimens. 



After the pelvis, the caudal vertebrse have, on each side, but 

 a single small and concave tubercle, nearly approached to the 

 suture of the annular part. They narrow, by degrees, to the 

 end of the tail, which terminates in a point. 



In entire individuals we may be assured that the tail is shorter 

 than the trunk by almost one-fourth of the length of the trunk, 

 and that the head is nearly one-fourth of the total length. These 

 proportions are taken on individuals of small dimensions. 



