132 EXTINCT MONSTERS. 



With regard to the place of Pterodactyls in the animal kingdom, 

 Professor Seeley places them as a distinct sub-class, side by side 

 with birds, and between mammals and reptiles, thus — 

 Mammalia. 



.S 



cn nj 



2 > 



O 

 Reptilia. 



The name Ornithosauria (bird-lizards) is frequently used 

 instead of the other name, because it expresses the idea of their 

 being partly saurian, and partly bird-like. 



They flourished from the period of the Lias to that of the 

 Chalk ; and then, like so many other strange forms, seem to 

 have suddenly disappeared. 



