250 Robert Harkness, Esq., on Fossil Footprints. 



amongst these we have representations of Chelonia, Sauria, 

 and Batrachia, the three forms of reptile life, the only one 

 Avanting being Ophidite, which, from its structure, could not 

 leave any traces of its former existence in the form of foot- 

 steps. With respect to the tracks which occur in the Pots- 

 dam sandstone, these shew their affinity to the steps of the 

 Emydian family of Chelonia ; and Professor Owen, from his 

 examination of them, refers them to this form, both owing 

 to the smaller size of the anterior extremities, and also from 

 their legs appearing to have been of shorter length than 

 those of land-tortoises. The fact of this animal having in 

 some of the steps left traces of reticulation, and a groove 

 which runs intermediate to the footprints of each side, leads 

 to the conclusion that this chelonia was furnished with a 

 projecting keel or plastron. Concerning the impressions 

 found in the Devonian at Elgin, these seem to have been 

 caused both by lizards and chelonia ; and the occurrence of 

 the Telerpeton Elginensis, a Lacertian form, which has left a 

 portion of its structure in the sandstone of this locality, 

 places us in possession of the oldest remains, except foot- 

 prints, which have yet been discovered of vertebrata. The 

 impressions which occur in the carboniferous rocks have, in 

 general, a Batrachian character. In the coal-measures of 

 Bavaria there have been obtained skeletons of reptiles, and 

 some of these, according to Herman Von Meyer, " were 

 provided with hands and feet, terminating in distinct toes ; 

 but these limbs were weak, serving only for swimming or 

 creeping." This anatomist shews that these reptiles have 

 some analogy to the Proteus anguinus, a reptile at the pre- 

 sent time inhabiting subterranean lakes. It is, however, in 

 the trias, the base of the secondary division of the geolo- 

 gical formations, that we have the most abundant evidence 

 of the former existence of reptile life, as left by their foot- 

 prints. In this formation they occur in the greatest plenty in 

 the Variegated sandstone (or Bunter sandstein)^ which forms 

 the lowest portion of the trias;* j ,..{ t m>w - •, ^ 

 f/ff^T c dtjv^ ?a'--*^ ^^ 



^- We prefer the name Variegated "Sanclstdn'e to the German one, Bant< r 

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