10 ON THE FOSSIL FOOTMARKS 



great part of the skeleton, with a mutilated portion of the cranium." Its osteological 

 characters are said to be " peculiar, exhibiting a blending of the true lacertian with batra- 

 chian attributes." Dr. Mantell has named it Telcrpeton Elg'mense, He also laid before 

 the society specimens of fossil ova which he considered to be unquestionably ova of 

 batrachian reptiles. (An. and Mag. of Nat. Hist., Jan., 1852.) 



Impressions in the plastic clay and sand of the shores of ancient lakes or rivers, left 

 by the inhabitants of their borders had been thus observed in the Coal Measures and the 

 superimposed strata, as well also their bones. When, in April, 1849, on a visit to the 

 coal district of Pottsville, Schuylkill county, Penna., I was fortunate enough to have 

 observed the "Foot-prints," in bas relief, of a reptiliaii quadruped^ in the Red Sandstones 

 of the eastern slope of Sharp Mountain, where the river Schuylkill makes its pass through 

 that rangeof mountains, an account of which I communicated to the American Philosophical 

 Society in June, 1849. (See Proceedings, vol. 5, p. 91 .) Its position was on the west side of the 

 turnpike road, about a mile east of the town of Pottsville, and a few hundred feet east of 

 Mount Carbon Hotel. The massive sandstone rocks here are of a beautiful red colour 

 and fine texture, evidently formed of sand and clay which had passed through much attri- 

 tion. The colour is due to a considerable charge of the red oxide of iron. Minute span- 

 gles of mica are generally interspersed throughout these rocks, and assist in giving the 

 surface of the fractures a soft and almost satin-like texture. The strata here are tilted 

 somewhat over the perpendicular, by the upheaval of this range of mountains; but the 

 surfaces which are exposed bear evidence of these sedimentary rocks having been de- 

 posited in a nearly horizontal position, in a placid state of water, presenting to the animal 

 a very slightly inclined shore, as it advanced from the waters which existed on the 

 northern side. The impressions made at that time were upon the sands of a shore from 

 which the waters had for a time receded, having left the shore covered with well defined 

 "ripple marks," and a profusion of "rain-drop pits." The surface of the rock exposed to 

 view was about six feet by twelve, and across the shorter diameter were distinctly and 

 beautifully impressed a double row of tracks, consisting of six impressions, duplicated by 

 the hind foot falling into the impression of the fore foot, but a little more in advance. 

 The specimen taken from the mass of the rock was thirty-four by twenty-one inches. 

 The six douhle imprcssio7is show, in the two parallel rows, formed by the left feet on the 

 one side and the right feet on the other, that the animal had five toes on the fore foot, 

 three of which toes were apparently armed with unguical appendages. The hind feet 

 appear to have had four toes. The impression of the hind feet being made nearly on the 

 same spot as that of the fore feet, cause some obliteration and confusion, as well as 

 variation in size and form of the "foot-marks.' The best defined one is four and a half 

 inches long and four broad — this is including the double impression. The single foot 

 would probably measure three and a half inches long by three inches broad. The stride 

 or step of the animal measures, from toe to toe, thirteen inches; from outside to outside, 

 the distance is eight inches. The mark of the tail is distinctly impressed, causing a 

 (^roove-like furrow on the top of each ripple line, oblique to their direction, and generally 

 five to six inches long and three-quarters of an inch wide. There are four of these tail- 



