1845.] BLACK ON FOOTSTEPS IN NEW RED SANDSTONE. 67 



Of the two tracks also, one was formed before the other, since one 

 of the footmarks in the longer track has obliterated part of the track 

 of the other, while the longer track is seen to have intersected and 

 to be deeper than the other. 



Similar tracks seen in relief have been attributed to the tails of 

 animals dragging over the surface of soft silt or clay, and in the 

 present case this explanation seems satisfactory. 



As to the nature and form of the animals which have left these 

 footprints, we can perceive that they had a strong resemblance to 

 recent Emydians in their mode of progression and in the form of 

 the foot ; and from the fulness of the relief observed, the animal must 

 have been of considerable weight in comparison with the length of 

 the foot. From the perfect definition of the tracks which appear to 

 have been caused by the tail, this organ would seem to have been 

 rather firm and short, and not long and pliant. 



The second class of well-defined impressions are marked (B) in the 

 accompanying plate. They consist of eight pairs running across the 

 breadth of the slab without interruption ; and there are also some 

 others whose connection cannot so easily be traced. The pairs of 

 these impressions, seemingly those of the fore and hind feet, run in 

 an alternate and oblique direction with respect to each of the other 

 pairs : only tliree toes can be readily made out in them, and they 

 belong to the larger and most probably the hinder feet. In some 

 places it appears that these hinder feet were not raised freely from 

 the ground at every step, for there are slight mouldings running 

 from the extremities of the longest toe as if it had been dragged 

 over the soft surface. These footsteps seem to have belonged to 

 some small species of land tortoise, and they exhibit neither the im- 

 pressions of a web nor of claws. 



The third class (C) exhibits six larger impressions, each accom- 

 panied by a smaller and more obscure one, and they run in one di- 

 rection across the end of the slab. There are also some others of 

 the same kind detached on otlier parts of the surface. These prints, 

 like the former set, are alternate and placed diagonally towards each 

 other. On a first inspection the larger of them resemble the im- 

 pressions of the feet of some birds, the toes being free and each ter- 

 minated by the well-marked impression of a claw ; but the number 

 of toes is five, placed in a radiating manner, and each print is ac- 

 companied by a smaller and fainter impression. The larger of these 

 prints therefore appear to have belonged to the hind feet, and the 

 smaller to the fore feet of an animal, which probably resembled the 

 smaller Lacertians or Alligators. 



The next set of impressions (D) are not so numerous as the 

 others, or at least the progressive connection is less easily made 

 out. A few of them however are sufficiently clear to enable us to 

 refer them to a species of reptile difl'erent from those already noticed. 

 Each impression exhibits four toes more or less apj)roximated to 

 each other, and showing indistinct nuirks of claws. Retwcen the 

 toes there may be detected traces of a web in some of the prints. 

 This web reaches nearly to the tips, and where the toes arc much 



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