DEVONIAN PLANT EEMAINS. 69 



Hayes Canyon has been eroded and where its geological relations with the 

 Nevada limestone below and the Diamond Peak quartzite above may be 

 easily recognized. The shale attains its greatest development east of 

 Sentinel Peak and Sugar Loaf, but as it is cut off from the Nevada lime- 

 stone by a north and south fault which passes up Rescue Canyon its 

 stratigraphical relations with the underlying strata are not as clearly shown 

 as at the first locality, while the overlying beds are buried beneath the 

 detritus of the plain. The thickness across the broadest part of the White 

 Pine shale east of Sugar Loaf may be placed at 2,000 feet. A marked 

 feature of the beds is the rapid changes which they undergo, both in their 

 lateral and vertical extension, passing abruptly from pure, argillaceous, black 

 shale into beds more or less arenaceous and frequently carrying interca- 

 lated beds of red, friable sandstone appearing as lenticular masses in the 

 shale. In Hayes Canyon the beds for the most part are brownish black 

 shale, with thin bands of red sandstone while opposite Sugar Loaf the inter- 

 calated red sandstone strata occasionally attain a thickness of 100 feet. Out 

 in the valley the lines between the shale and sandstone may be easily fol- 

 lowed for long distances, the former occupying shallow, trough-like depres- 

 sions and the latter low intervening ridges slightly elevated above the gen- 

 eral level. Cross sections made at no great distances apart differ widely 

 in the character of the sediments. All evidence indicates a shallow-water 

 deposit. The formations at Eureka and White Pine are identical in every- 

 way except in thickness of deposits, at the latter locality measuring not 

 more than 600 feet. 



Plant Remains in white pine shale. Impressions of plants which are exceed- 

 ingly rare in Paleozoic rocks of the Great Basin are very abundant and 

 form a distinctive feature of this epoch, notwithstanding that everything 

 which has been collected is of fragmentary nature. The most promising 

 specimens for identification were submitted to Sir J. William Dawson, 

 who, in his report, called attention to the poor state of preservation of the 

 plants. Under date of Montreal, June 11, 1889, he writes: 



One slab contains a small ribbed stem referable to Goeppert's Anarthrocanna, 

 a doubtful Calamitean plant. The specimen is not unlike those found at Perry, in 

 Maine, and Bay de Chaleur. On the large slab is also a slender branch stem which I 

 suppose may be the stipe of a fern, and from its character and angle of ramification 



