Footsteps in the Bunter Sandstone of Dumfries-shire. 207 



affords us. The sandstone on the south-eastern pai'ts of the 

 county appears to be higher in position than this latter bed, and 

 there is reason to conclude that 100 yards at least lie above 

 the conglomerate, thus making the flags in which fossil steps 

 abound, at least 300 yards below the infra-gypseous clays of the 

 Keuper. The conglomerate, which is entirely a local deposit, and 

 one which would accumulate much more rapidly than the com- 

 mon sandstones, renders it difficult to assign an exact position to 

 the impressions ; and the probabihty is that a comparison with 

 localities where no conglomerate occurs would give us a thickness 

 of Bunter sandstone not much exceeding the combined thickness 

 of the higher and lower deposits exclusive of the conglomerate. 



From this circumstance we find that, so far as the traces of 

 footsteps are concerned, had we been led to infer their position 

 in the Bunter sandstone generally, without taking the more rapid 

 accumulation of the conglomerate as it occm-s in Dumfries-shire 

 into consideration, we should have placed them more than SOO 

 yards below the Keuper, where it is probable that the real depth 

 does not greatly exceed 200 yards from that deposit. With re- 

 gard to the different kinds of tracks which are met with at Corn- 

 cockle, two of these are also found in the quarries of the sand- 

 stone in the neighbourhood of Dumfries, viz. the impression 

 which in front resembles the segment of a circle, and in which 

 the sand is thrown backwards during the progression of the ani- 

 mal ; and the other, the small impression in which toes and 

 cushions of the foot are well marked. This latter footmark we 

 find associated with the tracks of the Rhynchosaurtts in the 

 new red sandstone at Western Point near Runcorn in Cheshire. 

 But no steps of this latter animal have hitherto been found in 

 Dumfries-shire, and as ample opportunities would have occurred 

 for discovering such steps had the animal which formed them 

 existed in this locality during the deposition of that portion of 

 the Bunter sandstone from which impressions are obtained, we 

 may infer that either the conditions necessary for its existence 

 did not prevail in Dumfries- shire, or that the animal was called 

 into being after the sandstone of the district had been deposited. 

 That this latter cause was most probably the reason why we have 

 no traces of the RhynchosauriLS in the lower portion of the Bunter 

 sandstone, we may infer from the circumstance, that three if not 

 more types of animals, which were occupants of our earth during 

 the more early portion of the period when the Bunter sandstone 

 was being deposited, had ceased to exist, inasmuch as we find no 

 traces of them in the higher beds of the sandstone. 



That the small, toed animal which has been commonly consi- 

 dered as a tortoise, and the Rhynchosaurus coexisted, we have 

 every reason to believe, but none of the impressions in Dumfries- 

 shire show that circumstance, neither do we obtain in the district 



