READING RIDDLES OF THE ROCKS 131 



instance, when vertebrae that seem illy adapted 

 for carrying the weight of a land animal are 

 found in company with huge limb-bones and 

 massive feet we may feel reasonably certain 

 that their owner passed at least a portion of his 

 time on terra fir ma. 



So much for the probabilities as to the cov- 

 ering of animals known to us only by their fos- 

 sil remains ; but it is often possible to go be- 

 yond this, and to state certainly how they were 

 clad. For while the chances are small that 

 any trace of the covering of an extinct animal, 

 other than bony plates, will be preserved, Nat- 

 ure does now and then seem to have relented, 

 and occasionally some animal settled to rest 

 where it was so quickly and quietly covered 

 with fine mud that the impression of small 

 scales, feathers, or even smooth skin, was pre- 

 served ; curiously enough, there seems to be 

 scarcely any record of the imprint of hair. 

 Then, too, it is to be remembered that while 

 the chances were very much against such pres- 

 ervation, in the thousands or millions of times 

 creatures died the millionth chance might come 

 uppermost. 



