ICHNOLOGY 1G7 



fore foot, and each being at nearly equal distances from the 

 next pair. The hind foot-print is about one-third larger than 

 the fore foot-print : it has five toes, but the front one only four ; 

 some of them exhibit a stunted rudiment of the innermost toe 

 or " pollex," which is the undeveloped one. The outermost toe 

 in the hind footprint is shorter and rather thicker than the rest, 

 and stands out like a thumb on the wrong side of the hand. 



With this general resemblance to the footprints of Laby- 

 rinthodon, from the new red sandstones of Europe, there are 

 well-marked distinctions. In the first place, the right and 

 left series of impressions are wider apart, indicative of a 

 broader-bodied animal. The front print in Batrachopus has 

 only four well-developed toes instead of five, as in Ldbyrin- 

 thodon ; it is also proportionally larger, — the fore foot in 

 Labyrinthodon being less than half the size of the hind foot. 

 The distance between the fore and hind print of each pair, 

 and of one such pair from the next on the same side, is nearly 

 the same in Batrachopus and Labyrinthodon. 



Genus Saueopus, Eogers. — Very similar footprints were 

 discovered and described by Mr. Isaac Lea in a formation of 

 red shales, at the base of the coal measures at Pottsville, 78 

 miles 1ST.E. of Philadelphia. These are of older date than the 

 preceding, inasmuch as a thickness of 1700 feet of strata 

 intervenes between the footprints at Greensfield and the Potts- 

 ville impressions. 



Professor H. I). Ptogers, in 1851, announced his discovery 

 in the same red shales, between the Devonian and carboniferous 

 series, of three species of four-footed animals, which he deems 

 to have been rather saurian than batrachian, seeing that each 

 foot was five-toed ; one species, the largest of the three, pre- 

 sented a diameter for each footprint of about two inches, and 

 showed the fore and hind feet to be nearly equal in dimensions. 

 It exhibits a length of stride of about nine inches, and a breadth 

 between the right and left footsteps of nearly four inches. The 



