94 



The mark of the dragging of the tail is distinct, and occasionally 

 slightly obliterates a small part of the impressions of the foot-marks. 

 The ripple marks are seven to eight inches apart, and very distinct, 

 as well as the pits of the rain drops. These foot-marks assimilate re- 

 markably to those of the recent Alligator Mississippiensis, and are 

 certainly somewhat analogous to the Cheirotherium. 



The geological position of this reptilian quadruped is of great in- 

 terest, from the fact, that no such animal remains have heretofore 

 been discovered so low in the series. Those described by Dr. King, 

 in the great western coal field, are only 800 feet below the surface 

 of the coal formation. (No. 13, of Prof. Rogers, the State Geologist.) 

 The position of the Pottsville " foot-marks" is about 8500 feet below 

 the upper part of the coal formation there, which is 6750 feet thick, 

 according to Professor Rogers, and they are in the " red shale,'''' (his 

 No. 11,) the intermediate silicious conglomerate (No. 12,) being 

 stated by him to be 1031 feet thick at Pottsville. These measure- 

 ments ivould bring these foot-marks about 700 feet below the upper 

 surface of the old red sandstone. 



A mass of coal plants exists immediately on the northern face of 

 the heavy conglomerate, here tilted ten degrees over the vertical, and 

 forming the crest and " back-bone" of Sharp Mountain. This con- 

 fflomerate mass is about 150 feet thick at the western side of the road 

 below Pottsville. On the same road side, about 1735 feet from these 

 coal plants, is the face of the rock, tilted slightly over the vertical, 

 and facing the north. It is proper to state, that the limestone of the 

 old red sandstone exists here, about two feet thick, and underlies 

 these " foot-marks" sixty-five feet. 



On the slab there are obscure remains of other organized matter ; 

 small spots, with filamentous radiations, and a small bone or seed- 

 like mark, which is difficult to make out. 



I was fortunate enough to obtain these impressions in a large and 

 heavy slab, which is now in my possession. 



It is my intention, when more at leisure, to make a more lengthened 

 and accurate description, with correct figures, of this remarkable and 

 interesting specimen, which exhibits on its table the record of the 

 oldest saurian yet observed. When finished, the paper will be sub- 

 mitted to the Society for publication in the Transactions. In the 

 meantime, T propose the provisional name o^ Sauropus primcevius. 



