NO. 9 



GRAND CANYON FOSSIL FOOTPRINTS— GILMORE 



impress, but the depth of the hindfoot impressions as a whole leads 

 to the conclusion that this digit was probably absent. An important 

 distinction is thus furnished also between Dolichopodus and Droino- 

 pus which in many other features closely approach each other. If 

 correctly restored the feet of Araeoscelis fulfil nearly all require- 

 ments for their correlation with the footprints called Droinopus 

 agilis by Marsh. 



Fig. 4. — Restoration of Araeoscelis. An animal whose foot, 

 limb, and body structure suggests the type of creature that made 

 the tracks of Dolichopodus. About i natural size. (After 

 Williston.) 



Resemblances in the general plan of the footprints here described 

 to the feet of Araeoscelis leave but little doubt of their reptilian 

 origin. 



NANOPUS MERRIAMI, new species 



Plate 4, fig. 2 



Type. — Catalogue number 11,146, U. S. N. M. One slab (ob- 

 verse) on which there is a consecutive series of tracks about 450 milli- 

 meters in length. 



