CHAPTER X.
THE SKELETON OF THE NEWT (Molge cristata).
I. EXOSKELETON.
The skin of the Newt is quite devoid of any exoskeletal structures. The only exoskeletal structures that the animal possesses are the teeth, and these are most conveniently described with the endoskeleton.
II. ENDOSKELETON.
The endoskeleton of the Newt, though ossified to a considerable extent, is more cartilaginous than is that of the frog. It is divisible into an axial portion including the vertebral column, skull, ribs, and sternum, and an appendicular portion including the skeleton of the limbs and their girdles.
1. The Axial Skeleton.
A. The Vertebral column.
This consists of about fifty vertebrae arranged in a regular continuous series. The first vertebra differs a good deal from any of the others; the seventeenth or sacral vertebra and the eighteenth or first caudal also present peculiarities of their own. The remaining vertebrae are divided by the sacrum into an anterior series of trunk vertebrae which bear fairly large ribs, and a posterior series of caudal vertebrae, all of which except the first few are ribless.