10 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. ']'] 



Type locality. — Hermit Basin, Hermit Trail, Grand Canyon Na- 

 tional Park, Arizona. 



Geological occurrence. — Coconino sandstone (about 20 feet above 

 the base), Permian. 



Description. — Stride 62 mm., width of trackvi^ay, 50 mm. Hind- 

 foot: Length 15 mm., width 12.7 mm.; four toes, the inner slender, 

 sharp, and closely parallel to the second, the two median toes parallel 



Fig. 5. — Nanopus merriami. Type, No. 11,146, U. S. N. M. Dia- 

 gram of series of footprints. About i natural size. 



and directed straight forward, tips acuminate, clawed. Outer toe 

 shortened and well set off from the third. Sole suboval, weakly im- 

 pressed, nearly as long as the toes. Length of digit I, 5 mm. ; digit 

 H, 7.5 mm. ; digit HI, 7.2 mm. ; digit IV, 4.5 mm. Forefoot: Length 

 about II mm., width 9.5 mm; three toes, outer slightly divergent, 

 inner and outer digits shorter than median and subequal in length. 

 Sole small, suboval, weakly impressed. Toes appear to bear slender, 

 pointed claws. Length of digit I, 4.5 mm. ; digit H, 6 mm. ; digit HI, 

 4.6 mm. The weight of the animal, judging from the depth of the 



