CHAPTER V.

THE COLD-BLOODED AIR BREATHERS OF THE GLOBE IN TIMES BOTH PAST AND PRESENT 89

PICTURE-HEADING--Reptiles of the Cretaceous Period. On land _Iguanodon_, 20 feet high, attacked by _Megalosaurus_; in the air _Pterodactyls_, or flying lizards; in the water _Ichthyosaurus_, _Mosasaurus_, and _Teleosaurus_, with _Plesiosaurus_ in the background. (From various sources.)