REPTILIA 141 



consists of an upper portion, the carapace, and a lowei 

 portion, the plastron. How are the other regions covered ? 

 What is the shape of the head? Is the mouth at the 

 front, or on the under side ? Where are the nostrils ? 

 Are the motions of breathing visible ? Is there a beak or 

 snout ? Do the jaws contain teeth f 



Do the eyes project ? Which is thinner and more 

 movable, the upper or lower lid ? Identify the third eye- 

 lid (nictitating membrane). It is translucent and comes 

 from, and is drawn into, the inner corner of the eye. It 

 cleanses the eyeball. Frogs and birds have a similar 

 membrane. The circular ear drum is in a depression back 

 of the angle of the mouth. What other animal studied 

 has an external ear drum ? 



The tortoise has a longer, more flexible neck than any 

 other reptile. Why does it have the greatest need for 

 such a neck ? Is the skin over the neck tight or loose ? 

 Why? 



Do the legs have the three joints or parts found on the 

 limbs of most vertebrates ? How is the skin of the legs 

 covered ? Do the toes have claws? Compare the front 

 and hind feet. Does the tortoise slide its body or lift it 

 when walking on hard ground ? Lay the animal on its 

 back on a chair or table at one side of the room in view 

 of the class. Watch its attempts to right itself. Are 

 the motions suited to accomplish the object ? Does the 

 tortoise succeed ? 



What are the prevailing colors of turtles ? How does 

 their coloration correspond to their surroundings ? 



What parts of the tortoise extend at times beyond the 

 shell ? Are any of these parts visible when the shell is 

 closed? What movements of the shell take place as it is 

 closed ? Is the carapace rigid throughout ? Is the plastron ? 



