THE SPINAL COLUJIN OF REPTILES. 163 



dorsal vertebrse, or those bearing the true ribs, 

 differ in number in the various species: the 

 ribs are attached to the transverse processes, 

 and join the sternum by cartilaginous elonga- 

 tions; although some of the anterior ribs, 

 and also of the posterior ribs, more par- 

 ticularly, have their extremity free and un- 

 attached, at least in many instances. 



In the crocodiles, the sternum, which is 

 broad and osseous anteriorly, is continued 

 beyond the limits of the chest, as a slender 

 cartilage along the centre of the abdomen to 

 its lowest margin ; and this cartilaginous con- 

 tinuation gives off on each side eight slender 

 cartilaginous ribs, pointing obliquely back- 

 wards, and terminating in the muscles of the 

 abdomen, which they support. These stemo- 

 abdominal ribs are not connected vfith the 

 spine, their extremities are free. 



There is a peculiarity in the neck of the 

 crocodile which may not be passed by ; we 

 allude to additional pieces to the transverse 

 processes of the cervical vertebras ; these pieces 

 overlap each other, and greatly impede the 

 lateral flexure of the neck, so that the animal 

 cannot turn suddenly and rapidly round, or 

 bend the neck sideways to make a snap. This 



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