NO. 3 



GRAND CANYON FOSSIL FOOTPRINTS — GILMORE 



43 



Description. — Stride about 36 mm. ; width of trackway about 

 ^^ mm. This small slab of reddish colored shale has impressed on 

 its surface some few beautifully preserved tracks (see pi. 14), al- 

 though the trackway as a whole is obscure in several important details. 



Fig. 19. — Dromillopus parvus. Type. No. 11,537, U. S. N. M. 

 Diagram of trackway showing tail drag. Broken lines connect the 

 supposed pes impressions of opposite sides. About natural size. 



This obscurity is due to two conditions, first, the intermingling on the 

 left-hand side of the tracks of two small animals ; and second, the 

 failure of one pair of feet to impress clearly. The feet most clearly 

 registered correspond almost precisely in size and in number and 

 arrangement of the digits with the so-called hind foot described by 



