162 



with the neural spine. They each develope a moderately long and slender diapophysis, two 

 prezygapophyses, looking obliquely inwards and upwards, and two postzygapophyses with 

 opposite aspects. The spine is long, trihedral, with a rough surface at the fore- and back- 

 part of its base, for the attachment of elastic ligaments. The pleurapophyses are bifurcate, 

 short, and developed chiefly in the anterior and posterior directions. 



Hunterian. 



735. A posterior dorsal vertebra of a Crocodile. 



The centrum is characterized by the absence of processes ; the neural arch by the great 



length of the diapophyses, which are notched at the end and present two surfaces, one for 



the head, the other for the tubercle of the rib, which is here characterized by its length, slen- 



derness, and its articulation at its thickened distal end with a semi-ossified hsemapophysis. 



| 



Hunterian. 



736. A lumbar vertebra of a Crocodile. 



The centrum is broader in proportion to its length than in the dorsal. The diapophyses 

 have no articular surfaces for ribs. The zygapophyses are more nearly horizontal than in 

 the dorsal and cervical series. 



Itunterian. 



737. A vertical longitudinal section of a lumbar vertebra of a Crocodile. 



It shows the compact bone upon the upper and under surface, and forming the anterior 

 concavity of the centrum. 



Hunterian. 



738. Six pairs of the hsemapophyses from the abdominal walls of a Crocodile. 



From their long and slender form they have obtained the name of abdominal ribs ; each is 

 divided into two parts, being ossified from two distinct centres. 



Hunterian. 



739. The anterior sacral vertebra of a Crocodile. 



The short and thick pleurapophyses are trihedral, expanded obliquely, truncate, and irre- 

 gularly notched at their extremities : they articulate with both the centrum and neurapo- 

 physis by a broad sutural surface, the limits of which are not yet obliterated. The anterior 

 articular cup of the centrum is expanded transversely by portions of the pleurapophyses : the 

 posterior surface of the centrum is rough and nearly flat. 



Hunterian. 



740. An anterior caudal vertebra of a Crocodile. 



Here the neural arch has become anchylosed to the centrum, and the short ribs to both 

 those parts. The centrum is characterized by the two articular tubercles (hypapophyses) at 

 its under and posterior part for the articulation of the hsemapophyses which have coalesced 

 at their extremities and developed a long compressed spine. 



Hunterian. 



