READING RIDDLES OF THE ROCKS 13^ 



entirely, of small, irregularly hexagonal horny 

 scutes, slightly thickened in the centre. The 

 quarries of lithographic stone at Solenhofen 

 have yielded a few specimens of flying reptiles, 

 pterodactyls, which not only verify the correct- 

 ness of the inference that these creatures pos- 

 sessed membranous wings, like the bats, but 

 show the exact shape, and it was sometimes 

 very curious, of this membrane. And each and 

 all of these wonderfully preserved specimens 

 serve both to check and guide the restorer 

 in his task of clothing the animal as it was in 

 life. 



And all this help is needed, for it is an easy 

 matter to make a wide-sweeping deduction, 

 apparently resting on a good basis of fact, and 

 yet erroneous. Remains of the Mammoth 

 and Woolly Rhinoceros, found in Siberia and 

 Northern Europe, were thought to indicate 

 that at the period when these animals lived 

 the climate was mild, a very natural inference, 

 since the elephants and rhinoceroses we now 

 know are all inhabitants of tropical climes. 

 But the discovery of more or less complete 

 specimens makes it evident that the climate 



