THE ANIMAL KINGDOM. 



109 



in their bodies, they are without fur, hair, or feathers, but 

 are covered either with scales, or are naked altogether. 



Reptiles are divided into Tortoises, Lizards, Ser* 

 pents, and Amphibia. 



Tortoises are at once distinguished by the double 

 casing in which their body is enveloped ; but this is not 



Fig. 64 



SKELETON OF THE TURTLE. 



a " shell." The upper portion, called the " Carapace," is 

 formed by the spreading out of the ribs until they unite 

 with the spinal column, and the underneath part of the 

 case, called the " Plastron/' is in reality the breast-bone 



