I 



Robert Harkness, Esq., on Fossil Footprints. 257 



it usually is accompanied by castings of Annelid forms, such 

 as would be caused by an animal occupying the same posi- 

 tion as this species now does. 



Concerning the Cheirotherium, its affinities to existing forms 

 are far from being discoverable. Batrachians are, however, 

 rarely occupants of a littoral zone ; but the small Bufo 

 riibeta is, in this country, met with under stones between 

 tide-marks, and the Cheirotherium may likewise have been 

 an occupant of the shore ; but the nature of this reptile and 

 its habits are involved in obscurity. 



The immense numbers of fossil footprints are evidence 

 that vertebrate animals existed in great quantities during 

 the period of the deposition of the Variegated sandstone ; and 

 yet, with the exception of the portion of the skeleton of the 

 Rhynchosaurus found at Grimsel, in Warwickshire, and a 

 tooth of a reptile called by Professor Owen, Labyrinthodon, 

 there are few or no traces of osseous remains. 



In the case of the Chelonia of this epoch, although their 

 tracks shew that they existed in great abundance, and pro- 

 bably were more numerous than the other reptilian forms, 

 still we have no traces of the solid structure. This may, in 

 fact, probably arise from the circumstance, that these animals 

 were inhabitants of the land rather than the littoral zone, 

 and that when they perished their bones would be exposed 

 to atmospheric influence, and consequently would soon dis- 

 appear, while the bones of such reptiles as were inhabitants 

 of the shore would become covered over by the deposits left 

 by each succeeding tide. 



It is probable that at this epoch there existed other forms 

 of organic life besides these which have left the impress of 

 their footsteps in what was originally the sand of an ancient 

 shore. The food required for both the Rhynchosaurus and the 

 Cheirotherium, which was probably the animal to which the 

 fossil tooth belonged, would shew that other animals were 

 contemporaneous with these ; and the circumstance that in 

 the muschel-kalk, or deposit of limestone, which in the con- 

 tinent is intercalated between the Variegated and Keuper 

 sandstones, large quantities of fossil shells occur, indicate the 

 existence of numerous forms of organic life. The presence 



VOL. LU. NO. CIV.—APRIL 1S52. R 



