92 



The great point now among geologists is to enlarge our know- 

 ledge of them by increasing and multiplying the facts. For this 

 purpose there have been many active observers in the field, and only 

 a few years since the scientific world was startled with the announce- 

 ment, by Dr. King, of Greensburg, Pa., of the fact, that he had dis- 

 covered unquestionable fossil foot-marks of reptiles in the sandstone 

 of the coal measures, in Westmoreland county, near that town. A 

 short time before this Mr. Logan had discovered, in the carboniferous 

 rocks of Nova Scotia, foot-marks which appeared to Mr. Owen to 

 belong to some unknown species of reptile. A communication was 

 made by Dr. King, to the Academy of Natural Sciences, December 

 17th, 1844, in which he gave the description and figures of a bird 

 and two " saurian reptiles." No saurian remains had, before these 

 announcements, been found lower in the series than the neiv red 

 sandstone, and this new fact created great interest among geologists. 

 Dr. King states the impressions to be " near 800 feet beneath the 

 topmost stratum of the coal formation." 



Mr. Lyell, in Silliman's Journal, July, 1846, describes his visit to 

 Greensburg, where he examined these foot-marks, and sustained Dr. 

 King's observation and description of them. He considered them to be- 

 long to the genus CheirotTierium. 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 so full of novelty and 

 interest that, when we reflect on its importance, all disappointment in 

 the abandonment of the spurious foot prints is forgotten:" and further 

 on he observes, that " here, in Pennsylvania, for the first time, we 

 meet with evidence of the existence of air-breathing quadrupeds, capa- 

 ble of roaming in those forests where the Sigillaria, Lepidodendron, 

 Caulopteris, Calamites, Ferns, and other plants flourished." 



In these papers of Dr. King and Mr. Lyell, it is not a little re- 

 markable that they both should have overlooked or passed unnoticed 

 the fact, announced by Mr. Lyell himself, three years before, in Silli- 

 man's Journal, that Mr. J^ogan had discovered foot steps in the car- 

 boniferous rocks of Nova Scotia, " constituting the first indications of 

 the reptilian class known in the carboniferous rooks." (Vol. 45, page 

 358.) 



The object of this communication is to announce to the Society, 

 that I have discovered the foot prints, in has relief, of a reptilian 

 quadruped, lower in the series than has yet been observed. On the 

 5th of April last, in the examination of the strata in the gorge of the 

 Sharp Mountain, near Pottsville, Pa., where the Schuylkill breaks 



