liobert Harkness, Esq., on Fossil Footprints. 255 



The Tortoises, the Lizards, and the Batracbians, which at this 

 epoch occupied places on the surface of the earth, must, from 

 their nature, have been different in their habits as well as in 

 the localities where they had their abode. And although we 

 meet with the impressions of these various reptiles under cir- 

 cumstances remarkably similar, and even in some instances 

 associated together, yet it by no means follows that all the 

 reptilian forms of life were of such a nature as to occupy the 

 same habitat, and require the same conditions and food for 

 their existence and development. 



With respect to the Chelichnus, we have already seen that, 

 from the nature of its footprints, Professor Owen regards it 

 as allied to the land-tortoises. With such an affinity it is 

 difficult at first sight to perceive how it came to leave so 

 abundant traces of its former existence on what was origi- 

 nally the sand of the sea-shore. The nature of its food, as 

 well as that of the land-tortoises now occurring, must have 

 been derived from the herbage which clothed the adjoining 

 land, and the frequency of its tracts indicates that its pre- 

 sence on the sea-coast was not a matter of comparative acci- 

 dent, but for the purpose of fulfilling some object connected 

 with its natural economy. Sir William Jardine has remarked, 

 that in the impressions of Corncockle Muir, the tracks gene- 

 rally run from west to east, or in a direction which appears 

 to have been from the water towards the land. Occasionally 

 tracks may be found running in an opposite direction, but 

 these are commonly faint and imperfect ; and Sir William is 

 of opinion, that the perfection and regularity of the tracks 

 in one direction is owing to the circumstance, that the re- 

 ceding tide had so saturated the sand with water that the 

 impressions became obliterated as soon as made, while on 

 the return of the animals sufficient dryness enabled the shore 

 to retain more distinct footprints. The uniformity in the 

 direction of these tracks seems to point out to something con- 

 nected with the mode of life of the types of Chelonia, which, 

 during the epoch of the new red sandstone, were inhabitants 

 of Scotland ; and it is probable that the forms of land-tor- 

 toises which at this time exist, have something connected 

 with their economy which will afford an insight into the mo- 



