564 MANUAL OF NATUKAL HISTORY. 



used in delicate mouldings in architecture, and 

 which is represented in France by the Caen stone ; 

 and in the upper Oolite the celebrated Portland 

 stone is found, so useful as a building material. 



With regard to organic remains, the Stonesfield 

 slate has furnished us with three little quadrupeds 

 of the size of a mole, allied to the Australian genus 

 Myrmecobius, and belonging to the extinct genera 

 Amphitherium, and Phascolotherium ; they are of 

 the lowest, or marsupial tribes of mammals : from 

 the same place jaws of other marsupials, species of 

 Thylacotherium, have been received. Reptiles of 

 several descriptions peopled the ancient earth during 

 this epoch, which was also an " age of reptiles." 



Some, as the Pterodactyles, were organized for 

 flying through the air like so many Vampire-Bats ; 

 others were adapted for frequenting river-banks and 

 marshes, like the Crocodiles and the Monitors ; and 

 others were entirely marine, propelling themselves 

 through the still, warm waters, by means of fin-like 

 paddles. 



The Pterodactyl^ or Flying-Lizards, were most 

 numerous during the Oolitic period, fourteen species 

 having been discovered in the Oxford stage of So- 

 lenhofen alone; they are also found in the Stones- 

 field slate of Oxfordshire and Gloucestershire. These 

 remarkable beings of a former creation were probably 

 nocturnal, and differed from all living and extinct 

 tribes of Reptiles, in the little finger of the fore-legs 

 being greatly elongated and enlarged, to support a 

 membranous wing, by means of which they were 



