ON THE FOSSIL FOOT-MARKS 
IN THE RED SANDSTONES OF POTTSVILLE.* 
When I communicated to this society, in 1849, the discovery of “foot-marks” of a 
Saurian animal in the “ red shale” formation, No. 11, of Prof. H. D. Rogers, near Mount 
Carbon, south of Pottsville, I mentioned that in characterizing and naming this new 
animal (Sauropus primeevus ,) I would at a future time offer to the society a more length¬ 
ened and accurate description, with correct figures of this remarkable and interesting 
specimen. A subsequent visit to the locality has not induced me to change my views as 
to its position in the series of the stratified masses of that district. 
After the discovery of this ancient Saurian had been made known, by my account of it 
in the Proceedings of this society, Prof. H. D. Rogers stated, at the meeting of the 
“American Association for the Advancement of Science,” at New Haven, that these 
“foot-prints in the red shale formation at Mount Carbon” were “of an age essentially 
later than that attributed to them,”—that “ they occurred in a geological horizon only a 
few hundred feet below the conglomerate which marks the beginning of the productive 
coal series, in which series similar foot-prints, attributed to batrachian reptiles, have been 
previously met with in Western Pennsylvania. Instead, therefore, of constituting a record 
of antique reptilian life, earlier than any hitherto discovered, by at least a whole chapter 
in the geological book, they carry back its age only by a single leaf.” 
These and some farther observations were followed by remarks of Prof. Agassiz on the 
character of these foot-prints, which he attributed rather to “ the pectoral and ventral 
fins of fishes of an ancient type, which probably had some power of locomotion out of 
water.”f 
At the meeting, in August, 1851, at Albany, Professor Rogers exhibited specimens 
which he had procured from the same formation, (No. 11,) near to the same locality. 
[* Read before the American Philosophical Society, April 2d, 1852, and published in the Transactions, 
Vol. X., New Series.] 
f Proceedings of the American Association, 1850, p. 251. 
