730 



vertical direction, producing an interlocking joint, combining strength with freedom of motion, 

 and analogous to that in the neck of birds. The pleurapophysial part of each transverse 

 process is a broad depressed plate, with its anterior margin produced, and progressively in- 

 creasing in size from the third to the sixth vertebra. A similar increase is presented by the 

 neural spines, especially in the sixth vertebra. 



4696. The seventh cervical vertebra. 



The transverse processes are simple diapophyses, and imperforate. 



4697. The fourteen dorsal and three lumbar vertebrae. 



The pleurapophyses are distinct from the diapophyses, are long and free, forming ribs. 

 Nine pairs of these directly articulate with the sternum, which consists of nine bones and an 

 ensiform cartilage. The metapophyses begin to curve inwards from the second dorsal verte- 

 bra, assume the form of a distinct plate in the tenth and eleventh, and separate from the ana- 

 pophyses in the thirteenth and fourteenth vertebrae. The first lumbar has no diapophyses, 

 but shows an articular surface for a pair of rudimental ribs. Broad, depressed diapophyses 

 are developed from the second and third lumbars. The anapophyses are suppressed on the 

 latter. 



4698. The sacrum and five anterior caudal vertebras. 



The sacrum includes four vertebrae by the anchylosis of the last lumbar, which is modified 

 and developed for articulation with the iliac bones. Tubercles analogous to metapophyses 

 and representing a second series of those processes are developed from the diapophyses of the 

 caudal vertebrae. 



4699. The four succeeding caudal vertebrae. 



They show the development of a pair of hypapophyses from the seventh, and the super- 

 addition and anchylosis of a haemal arch to those of the two succeeding caudals, in which the 

 diapophysis is divided into an anterior and posterior portion. The neural canal becomes 

 exposed in the ninth vertebra. 



4700. The four succeeding caudal vertebrae, being the tenth to the thirteenth in- 

 clusive. 



They show the great length of the hypapophyses, to which hsemapophyses have not been 

 attached. The anterior zygapophyses cease to be developed from the metapophyses in these 

 and the following caudal vertebrae. 



