6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8o 



ichnite fauna was confined to the two species mentioned above. Under 

 the guidance of G. E. Sturdevant, who had previously made one or 

 more prospecting trips over the Hermit shale at the head of Hermit 

 Gorge (see pi. i, figs. I and 2), we were led without loss of time to 

 the locality from which many of the specimens described in this 

 paper were collected. This locality may be roughly stated as being 

 about one-quarter of a mile west of the sign " Red Top " on the 

 slopes facing north or toward the entrance of Hermit Gorge into the 

 main Canyon of the Colorado, and from 30 to 40 feet above the 

 Hermit-Supai contact. The red shales that carry the tracks and plant 

 remains lie in troughs eroded in the upper part of the Supai sand- 

 stone (see fig. 2). In some instances the knolls of sandstone rise 

 so feet above the base of the hollow, and all of the tracks found 



Fig. 2. — Diagram to illustrate erosional contact between the 

 Hermit shale and Supai sandstone, and to indicate the position 

 of the track and plant bearing horizon at X. (Modified from 

 Schuchert.) 



in situ came from two levels, one about 30 feet and a second 40 feet 

 above the base of one of these troughs. Both track and plant remains 

 were found also on the loose slabs covering these slopes even well 

 around toward the head of Hermit Gorge opposite " Dripping 

 Springs," but, as previously mentioned, only two thin layers were 

 found in place. Noble,^ however, reports finding plant remains " from 

 beds at the base of the Hermit shale resting in depressions in the 

 unconformity near ' Red Top ' in Hermit Basin." 



The Hermit shale, so named by Noble in 1922, was formerly in- 

 cluded in the Supai formation and has a thickness in the Hermit 

 Trail section of 317 feet measured from the base of the deepest 

 depression in the disconformity in the top of the Supai, and 26"/ feet 

 measured from the top of the highest knoll. 



The Hermit shale is described by Noble as follows : ' 

 The beds differ little from one another in composition and consist essentially 

 of sandy mud colored red by ferritic pigment. The beds that I have desig- 



* Prof. Paper No. 131, U. S. Geol. Surv., 1922, p. 66. 

 " Op. cit., pp. 64-65. 



