76 



OOLITE. 



In the English lias there is a vast abundance of the enalio- 

 sauria which we have seen commence in the foreign Muschel- 

 kalk, and, in addition to these, specimens of Pterosauria, or 

 Winged Saurians, a type of being, the most novel, perhaps, of 

 all which the geological record has presented to us. The 

 Pterodactyls, as the animals of this character have been called, 

 were saurians possessed of bat-like wings extended upon the 

 fore-finger, by which the animal was enabled to pursue its 

 way in the air. This genus became extinct in the time of the 

 chalk formation. The only existing animal of which it may 

 even remind us is the draco volans, or flying lizard, which has 

 a membrane by which to support itself in leaping from tree to 

 tree. 



FIG. 57. 



Pterodactylus crassirostris. 



In the proper oolite, there is added an enaliosaurian (the 

 Pliosaur) in which there is a very close approach made to the 

 crocodilian order, but upon a scale of enormous magnitude, the 

 animal having apparently been as large as the existing whales. 

 Here, too, we find the true crocodilia largely developed, and 

 five genera have been described (Teleosaurus, Steneosaurus, 

 Cetiosaurus, &c.) The two first are like crocodiles of our own 

 time in all respects, except a somewhat greater bulk, and cer- 

 tain peculiarities indicating more aquatic habits. The last 



