AGE OF REPTILES. 



249 



in some cases, even thirty feet in length. One of its pad- 

 dles contained over a hundred bones, giving this instru- 

 ment great elasticity and power. Thirty species of this 

 animal have been discovered. 



354. Flesiosaurus. This animal, of which you see the 

 skeleton represented in Fig. 149, had the general plan of 



Fig. 149. 



the Ichthyosaurus, but differed from it in several mate- 

 rial particulars. It was fitted for more brisk motion. 

 Its head was flat and serpent-like. It had a very long 

 neck, its paddles were large but slender, and its tail 

 short. In swimming, it probably used its paddles more 

 and its tail less than the Ichthyosaurus. The greatest 

 difference, however, is in the size of the head. The 

 length of the Plesiosaurus was about 17 feet. Both ani- 

 mals had the power of creeping on land. 



355. Pterodactylus. The Pterodactyl is the most ex- 

 traordinary of the animals of this period. It had the 

 head and neck of a bird, the mouth of a crocodile, the 



