8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8o 



This ichnite fauna is quite distinct from that of the Coconino which 

 came after, or the Supai which preceded it. 



Siipai formation. — The Supai formation in the Hermit Trail sec- 

 tion, as estimated by Noble,' has a total thickness of 950 feet. The 

 first evidence of footprints occurring in this formation was noted by 

 Schuchert in IQIS."" Apparently no one gave the discovery further 

 attention until 1925 when well defined tracks were found by G. E. 

 Sturdevant on loose blocks of sandstone lying below the new Yaki 

 Trail on the north end of O'Neill Butte, at a point slightly more than 

 two miles down from the top. This information was, together with 

 other discoveries made in the same locality, given to me by Superin- 

 tendent J. R. Eakin. In all of the early discoveries the tracks were 

 on detached blocks found lying on the hillside, and it was not until 

 the late winter of 1926 that Dr. John C. Merriam of the Carnegie 

 Institution of Washington, accompanied by Mr. Sturdevant, found 

 tracks in situ (see pi. 2, fig. 2). These were in a sandstone layer 

 estimated to lie in about the middle of the formation. 



Unaware, at the time, of Schuchert's previous discovery of tracks 

 in the Supai, I made this locality the first object of search in the 

 spring of 1926, accompanied by Mr. Sturdevant. Our prospecting 

 disclosed many additional tracks and we located a second track-bearing 

 horizon in a light colored sandstone some 30 feet above those found 

 by Merriam and Sturdevant. 



Numerous tracks and trackways were found on blocks of stone 

 in the debris which had been thrown below the trail in the course of 

 excavating. No further attention was given the Supai tracks until 

 near the close of operations when an attempt was made to locate 

 these same track-bearing horizons in the Hermit Trail section in order 

 that they might be considered with the other track- bearing formations 

 in a single geological section. In this we were successful, finding the 

 first recognizable footprints in a whitish friable sandstone to the 

 left and below the Hermit Trail at a point about one-half mile below 

 " Santa Maria Spring." Rather poorly preserved tracks of at least 

 three kinds of animals were seen. The most distinct series collected 

 is shown in plate 21. This is probably the same horizon in the for- 

 mation in which Schuchert made the original discovery. The follow- 

 ing day search was made for the lower horizon and passing backward 

 underneath the clifif after descending the first short zig-zags above 

 " Breezy Point," tracks were found, thus establishing their position 

 in the section as identical with those previously found in the Yaki 



' Op. cit., pi. 19. 



'Amer. Journ. Sci., Ser. 4. Vol. 45, p. 357. 



