204 Dr DUNCAN on the Footmarks of Quadrupeds 



state, seems to be deducible from the appearances connected 

 with these impressions. It has been alleged that the materials 

 of which sandstone is composed, were accumulated by succes- 

 sive depositions from the sea or other extensive waters, and that 

 therefore the strata must have been, while in a soft state, nearly 

 horizontal. It seems almost demonstrable, however, that the 

 strata must in this instance have been in a greatly inclined po- 

 sition, if not altogether as inclined as at present, when the im- 

 pressions were made. On this subject an observation or two 

 may suffice. On inspecting the casts and specimens sent, it 

 will be observed that there are evident remains of the matter 

 displaced by the footsteps. This is the case with almost all the 

 impressions I have seen ; and wherever such an appearance 

 occurs, that matter is found to have been carried downwards, 

 with reference to the present inclination. In the case of No. 2, * 

 for instance, the track of ,the animal was directly up the face of 

 the steep ; and it will be seen that the'sand is therefore thrown 

 back, immediately behind the foot-marks. In the case of No. 1, 

 however, the track had inclined a little to the right, and this 

 slight variation is indicated by the direction of the displaced 

 sand, which has precisely such a position as this circumstance 



the more than usual soft condition of the sand at the time and place where these im- 

 perfect marks were made. Marks exactly like those made by my living tortoises, 

 on sand that was wetted too much for a sound impression, viz. holes into which the 

 foot had sunk so deep that it could not be lifted out and moved forward by the ad- 

 vancing animal without displacing by its toes a quantity of the sand that was in front 

 of the line of motion of each foot, and the result being a series of scoopings such as 

 the track of a hare or rabbit exhibits in soft and deep snow. If this idea be correct, 

 the impressions may have been made on horizontal beds of soft sand, ere they had 

 received the high degree of inclination they now possess. Thus the problem will be 

 relieved of some portion of its difficulty, namely, that which attends the hypothesis 

 of all the impressions having been made on the sand-beds whilst inclined at the same 

 angle they exhibit at present." 



* The casts and specimens here alluded to are deposited in the Museum of the 

 Society, and may be inspected by application to any of its members. 



