THE LIZARD 



361 



body and bringing the sticky end in contact with its prey. 

 The protrusions and retractions of the tongue take place with 

 marvellous rapidity (Fig. 338). 



While in point of size the lizards of geologically recent times 

 are inconsiderable, those of former epochs were huge. These 



Fig. .3.39. 



Hadrosaurus. From reconstruction model. Owijorn, " Rept. 

 Amor. Mus. Nat. Hist." 



former or fossil lizards were most characteristic of the middle 

 life era or the Mesozoic age. They belong to three main 

 groups ; namely, swimming, walking or wading,' and flying 

 lizards. The swimming lizards were sometimes over 10 metres 

 long, and had feet modified as paddles. The land lizards 

 were elongated, three-toed, carnivorous reptiles, with hollow 

 leg bones like birds. In the flj'ing lizards a strong, compact 

 body was provided with hollow, air-filled bones, and locomo- 



' Fig. 339. 



