254 Robert Harkness, Escj., 07i Fossil Footprints. 



which this formation contains in other localities ; and the 

 position in which they occur in the Variegated sandstone in 

 this county, is such as to lead to the conclusion, that here 

 they occupy a lower zone than any which have hitherto been 

 found in the Variegated sandstone. In the Cheshire beds of 

 new red sandstone, we also find impressions caused by Che- 

 Ionia apparently allied to the genus Chelichnus, and, along 

 with this step, we have the footprints of the Lacertians in the 

 form of the Rhynchosaurus ; and also of the Batrachians, as 

 represented by the tracks of the Cheirotherium. Ail these 

 forms are seen associafed in the new red sandstone of Weston 

 Point, where they are seen in the form of natural casts on the 

 under surface of one of the beds of sandstone lying upon a 

 thin deposit of red clay, over which these animals had for- 

 merly traversed. Impressions of the Rhynchosaurus are also 

 obtained from the trias of Warwickshire, and elsewhere in 

 this deposit in England. In Cheshire, the highest beds of 

 the Variegated sandstone contain commonly only the steps of 

 the large Cheirotherium, and this form of step is frequently 

 seen in the higher beds of this deposit on the continent. It 

 would appear that during the epoch occupied by the deposition 

 of the Variegated sandstone, there had been three distinct 

 creations separated from each other by certain periods, during 

 which more than one species of reptiles have ceased to exist. 

 First and lowest, there was the epoch of the Chelichnus, the 

 Herpitichnus and the Lacertians and Batrachians, which in- 

 habited our earth in the earliest epoch of the trias, and which 

 had, to a great extent, disappeared when the next form, the 

 Rhynchosaurus, makes its appearance. This Lacertian type 

 occurs in the greatest abundance during the interval which 

 separates the Chelichnus and its contemporaries from the era 

 of the Cheirotherium ; and this latter form occurs usually in 

 the higher beds of the Variegated sandstone, where it is in- 

 terstratified with beds of blue, red, and white clays, a circum- 

 stance which shews an approximation to the superior deposit 

 of the trias, — the Keuper. It would, therefore, appear that 

 in Dumfriesshire there existed reptilian forms previous to 

 those which have impressed the sandstone of England with 

 their footsteps. 



