THE CRUST OF THE EAKTH. 



certain places, had a still greater thickness. In fine, at a later 

 period still, another great elevation of the crust took place, which 

 raised the surface to its present elevation above the waters. 



181. Independently of the evidence supplied by organic remains 

 proving that certain strata were at former epochs above the waters 

 and inhabited by land animals, and were subsequently submerged, 

 indications of another order have been supplied by the traces left 

 by animals in the soft surface of the strata, which were afterwards 

 hardened without these traces being effaced. Such traces, there- 

 fore, may be regarded as moulds thus accidentally preserved, from 

 which castings might be obtained of those parts of the animals, 

 then living upon the globe, which produced them. Many moulds 

 of shells have been thus found, but the most remarkable indica- 

 tions of this kind consist of the footsteps of certain animals which 

 appear to have been impressed upon the soft surface of the ground, 

 just as the footsteps of any animals might be at present impressed 

 upon the soft sand upon the sea-shore after the retirement of the 

 tide. 



182. In 1834 an account was published of remarkable fossil 

 footprints in the new red sandstone at Hesseburg, near Hildburg- 

 hausen, in Saxony. The largest of these tracks appears to have 

 been made by an animal whose hind-foot was eight inches long, 

 and which, from its resemblance to the human hand, received 

 from Professor Kaup the name of Chirotherium. Some of the 

 tracks, however, appeared to be those of tortoises ; and Link sug- 

 gests that others are those of some colossal species of frog or sala- 

 mander, fig. 109. * 



Fig. 109. Labyrinthodon pachignatus (Owen). 



The traces represented in fig. 108 are those found in a sand- 

 stone slab at Hesseburg. Various similar tracks have been found 

 in the sandstone quarries at Storeton Hill, near Liverpool. The 

 largest footprint was nine inches long and six inches broad, the 

 length of the step being nearly two feet. Similar tracks were 

 found by Professor Hitchcock in the quarries of Connecticut ; and 

 Mr. Scrope found similar marks on a surface bearing ripple-marks 

 in the vast marble- quarries near Bath. 

 134 



