found in Sandstone in Dumfriesshire. 205 



accounts for ; while in the case of No. 3, the wet sand has evi- 

 dently run down before the descending prints. It will be ob- 

 served, too, that the claws and fore-part of the ascending foot 

 have been more deeply inserted into the sand than would have 

 been natural, had the surface been nearly horizontal ; and indeed 

 a slight glance at the sliding foot-marks in No. 3, seems to settle 

 the question. But there is another circumstance already men- 

 tioned, which can scarcely be accounted for, but on the supposi- 

 tion that the surface of the sand had a very considerable inclina- 

 tion, I mean the fact that the tracks run all from the bottom to 

 the top of the slope, or vice versa, and never across. An inclina- 

 tion of 38 is so considerable, that it could only be with extreme 

 difficulty that an animal could make its way across the steep ; 

 but it would obviously find a-mueh less effort necessary in moving 

 up and down. 



With regard to the state of the sand, in point of tenacity and 

 moisture, at the time the impressions were made, a few remarks 

 seem to be called for. In the first place, the surface could not 

 have been entirely dry, otherwise the displaced sand would have 

 been rough and uneven, whereas it is quite smooth, indicating a 

 state inclining to mud, which may be explained on the supposi- 

 tion already mentioned, of a considerable mixture of fine particles 

 of clay ; but on the other hand, had the matter been very soft, it 

 could not have retained its precipitous face, nor could the animals 

 have moved over it, without sinking much deeper than they ap- 

 pear to have done, neither could the impressions have remained 

 so distinct as we find them actually to be. There seems to be an 

 indication, too, of a certain degree of toughness in the surface. 

 This is particularly remarkable in No. 2, where it would appear 

 that the clayey sand had already become slightly indurated ex- 

 ternally, having been skinned over, as it were, with a stiffening 

 coat ; for it will be observed that the claws of the animal as it 

 ascended, seem to have rent the surface asunder at every step of 



