ICHNOLOGY. 191 



these footprints, though with a surmise of the possibility of 

 their marsupial nature.* 



Genus Bateachopus (Batrachqpus primcevus, King.) — In 

 1844, Dr. King of Greensburg, Pennsylvania, discovered fossil 

 footmarks, which he announced as being those of a reptile, 

 in the sandstone of the coal measures, near that town. No 

 reptilian footprints had previously been found lower in the 

 series than the New Eed sandstone. Dr. King states the 

 impressions to be " near 800 feet beneath the topmost stratum 

 of the coal formation." 



Sir C. Lyell, in Sillimarts Journal, July 1846, describes 

 his visit to Greensburg, where he examined these footmarks, 

 and confirmed Dr. King's description of them. He considered 

 them to be allied to the labyrinthodont footprints which have 

 been referred to the genus Cheir other ium. He says — "They 

 consist, as before stated, of the tracks of a large reptilian 

 quadruped, in a sandstone in the middle of the carboniferous 

 series, a fact full of novelty and interest ; for here in Pennsyl- 

 vania, for the first time, we meet with evidence of the exist- 

 ence of air-breathing quadrupeds capable of roaming in those 

 forests where the Sigillaria, Lepidodendron, Caulopteris, Cala- 

 mites, ferns, and other plants flourished." 



These footmarks were first observed standing out in relief 

 from the lower surface of slabs of sandstone resting on thin 

 layers of fine unctuous clay, which also exhibited the cracks 

 due to shrinking and drying. Now these cracks, where they 

 traversed the foot-prints, had produced distortion in them, for 

 the mud must have been soft when the animal walked over it 

 and left the impressions ; whereas, when it afterwards dried up 

 and shrunk, it would be too hard to receive such indentations, 

 and could only affect them in the way of subsequent dislocation. 



No less than twenty-three footsteps, the greater part so 

 arranged as to imply that they were made successively by the 



* Ichnology of Massachusetts, 4to, 1858, p. 123. 



