MARTIN: A GIGANTIC AMPHIBIAN. 113 



EXPLANATION OF PLATE IL 



Photograph of the east bank of the Wakarusa creek at Dightman's crossing, 

 five miles southeast of Lawrence, Kan., showing the relation of the heavily 

 bedded sandstone, in which the amphibian footprints were found, to the 

 Weston shales which outcrop immediately at the edge of the water. The 

 ravine in the center of the picture has a depth from the surface of twenty 

 feet, and in this depression, on the ledge indicated at the point of the arrow, 

 was found the series of footprints shown in the plate. This ledge at the 

 position of the first track lies fourteen feet above the creek, but the stratum 

 rises three feet between the first and the second impressions, between which 

 there is an eroded interval of twelve feet. A further inclination of the 

 stratum is indicated in the fact that there is a rise of four feet between the 

 second and the last impressions, a distance of twenty-seven feet. The ledge 

 on which the impressions were found is continued into the sandstone chff 

 immediately above the star (*). 



8 — Science Bui. — 3728 



