104 PKACT1CAL ZOOLOGY. 



11. How does the turtle draw in its head? 



12. How long does the heart beat after the head is 

 cut off? 



THE SKELETON OF THE TURTLE. 



1. Clean away the muscles and all soft parts. Boiling 

 loosens the outer plates ; these are part of the skin, 

 and not of the skeleton proper; they are called the 

 epidermal plates. 



2. When these plates are removed from the carapace, 

 there appears a series of bones extending outward on 

 each side ; these are the ribs, very wide, and united 

 by their edges. How many of these flattened ribs 

 are there ? 



3. On looking at the inner surface of the carapace, the 

 series of vertebrae will be found ; and attached to the 

 sides of the bodies of these vertebrae are the heads of 

 the ribs. 



4. Along the middle line of the outside of the carapace 

 between the ribs of the two sides, is found a series of 

 bony plates ; these are the enlarged and flattened pro- 

 jections of the vertebrae ; they correspond to the 

 spines which make the sharp ridge along the backs of 

 most vertebrates. 



5. Compare the bones of the pelvis and of the limbs 

 with those of the rabbit. 



For a full account of the anatomy of a turtle, see " How 

 to Dissect a Chelonian," by Prof. H. N. Martin and 

 Dr. W. A. Moale. 



For finding the names and classification of turtles, use 

 Jordan's " Manual of the Vertebrates." 



