NO. 9 



GRAND CANYON FOSSIL FOOTPRINTS GILMORE 



21 



digits, the imprint called hindfoot by Matthew certainly bears a 

 closer resemblance to the track of the manus in B. eakini than to that 

 of the pes. Furthermore, the subtriangular sole of the so-called 



Fig. 13. — Baropesia abcissa Matthew. A, Mould of right hind- 

 foot; B, mould of left forefoot, i natural size. (After Matthew.) 



forefoot has its nearest counterpart in the pes of B. eakini. For 

 these reasons it would appear that B. sydncnsis also agrees with B. 

 eakini in planting the forefoot in front of the hind instead of behind 

 it as originally determined by Matthew. 



Fig. 14. — Restoration of Cacops aspidephorus Williston, a stego- 

 cephalian amphibian from the Permian of Texas. (After 

 Williston.) 



The average distance between fore and hind tracks of the same 

 side of B. eakini is about 16 millimeters. The feet turn in strongly 

 toward the median line of the trackway. The front of the feet is 

 always deepest impressed, probably because the animal was climbing 

 a slope, an inference substantiated by the flow structure behind the 

 tracks made by the material displaced by the feet. The toes of 



