NO. 9 GRAND CANYON FOSSIL FOOTPRINTS GILMORE I 5 



two and three are parallel, subequal in length, and distinctly sepa- 

 rated. The palm is narrow antero-posteriorly, with the heel strongly 

 rounded off toward the external side. In all of these respects the 

 new material is in perfect accord with the excellent impression of 

 the forefoot of the paratype, as shown in figure 9A. This figure 

 was made from a cast, the specimen showing the obverse side of 

 the imprint only. 



The digits of the pes, instead of being short and blunt as origi- 

 nally depicted, are relatively long and distinctly separated. Only one 

 of the footprints on the slab numbered 11,122 shows any evidence 

 of a fifth toe (see fig. 9C) and its presence in the other tracks of 

 this genus and species would be unsuspected if it were not for the 



Fig. 9. — Laoponis iiobcli Lull, A, Outline of left forefoot. Para- 

 type, No. 8,422, U. S. N. M. B, C, Fore- (right) and hindfeet 

 (left) of No. 11,122, U. S. N. M. All | natural size. 



claw drag showing five in the paratype. The evidence is conclusive in 

 this respect, as first recognized by Lull, for where the creature 

 dragged the hindfoot of the left side there are five distinct narrow 

 scratches. The first toe, although relatively short, is distinct ; the 

 second, third, and fourth are of subequal length ; the fifth is seldom 

 plainly impressed. All are acuminate. 



A critical examination of Lull's illustration of the type ' specimen 

 shows that the imprints are rather shallowly impressed and for that 

 reason fail to give a true conception of the foot plan, especially as 

 to the character of the digits. This will explain the great disparity 

 existing between the original figures and the present conception (see 

 fig. 9) based upon more abundant and better preserved specimens. 



^ Loc. cit., pi. 2, fig. I. 



