On. XXV.] FOOTPEIXTS OF AIE-BREATH1XG REPTILES. 



507 



skin, which consisted of long, narrow, wedge-shaped, tile-like, and 

 horny scales, arranged in rows (see fig. 558). 



Cheirotkerian Footprints in Coal-measures, United States. — Id 

 1844, the very year when the Apateon or Salamander of the coal 

 was first met with in the country between the Moselle and the 

 Rhine, Dr. King published an account of the footprints of a large 

 reptile discovered by him in North America. These occur in the 

 coal-strata of Greensburg, in Westmoreland County, Pennsylvania; 

 and I had an opportunity of examining them in 1846. I was at once 

 convinced of their genuineness, and declared my conviction on that 

 point, on which doubts had been entertained both in Europe and the 

 United States. The footmarks were first observed standing out in 

 relief from the lower surface of slabs of sandstone, resting on thin 

 layers of fine unctuous clay. I brought away one of these masses, 



Fig. 559. 



Scale one-sixth the original. 



Slab of sandstone from the coal-measures of Pennsylvania, with footprints of air 



breathing reptile and casts of cracks. 



