122 PICTURESQUE SKETCHES 



of reptiles are so rare in the older rocks, only a very 

 few instances of them having as yet been met with, 

 we no sooner enter on the examination of the new 

 red sandstone, than we find indications of the exis- 

 tence of several remarkable forms. These soon in- 

 crease so rapidly, that by far the most striking and 

 characteristic organic remains of the next succeed- 

 ing period are reptilian, proving that such animals 

 were then at least, if they had not been before, among 

 the most important of the inhabitants of the sea. 



It is not an unusual thing, in examining sandstone 

 rocks, to find indications not only of an ancient sea 

 bottom, but also of that intermediate space between 

 the reach of the highest tides and low water which 

 formed the actual sea-shore, and was exposed alter- 

 nately to be trodden on and indented by various 

 animals moving over the damp sand, and to the in- 

 fluence of the waves of the sea. Among the more 

 common indications of this state are the ripple-marks 

 often seen on sandstone, and many irregularities of 

 surface, apparently produced by the passage of worms, 

 crabs, star-fishes, &c. 



Of all the ancient lines of sea-coast that have yet been 

 introduced to our notice, there is none more interesting 

 than that of the new red sandstone sea, for we find 

 there not only marks of worms and the ripple of 

 the water, but almost every other marking that can 

 be imagined likely to have been made under such 

 circumstances; and among these are distinct traces of 

 the passage of numerous four-footed animals of many 

 different kinds. Every one will remember the asto- 

 nishment which Robinson Crusoe is represented to 

 have felt at the sight of a human foot-print on the 



