FOSSIL FLORA. 787 



also makes their determination certain. Several other species, having a 

 wider distribution, are very abundant in these beds, such as Aralia notata, 

 which is represented by more than 100 specimens, and Sequoia langsdorfii, 

 which has a wide distribution, but is most abundant in this country in 

 the Fort Union beds. Sequoia couttsice, having a somewhat wide range, is 

 also very abundant in the beds under consideration and the Fort Union. 

 Besides these are a number of species that can not be mistaken, as Zizyphus 

 serrulatus, Taxites olriki, etc. 



One species, Asplenium erosum, has been found in both Laramie and 

 Denver strata in Colorado. It is represented by only 2 or 3 small and 

 more or less doubtful examples from the Yellowstone below Elk Creek. 

 Juglans rugosa is a species of wide distribution and therefore of compara- 

 tively little value stratigraphieally. It is found from the Laramie to the 

 Miocene, but is rare in the acid beds within the Park. Quercus olafseni has 

 been found in the Laramie, but its determination in the Park depends on a 

 single doubtful fragment from the vicinity of Elk Creek. 



The species that have also been found in the Green River beds are 

 comparatively unimportant. Lygodium haulfusii is, in this country, a typical 

 Green River species. It is rare in the acid series, but abundant in the basic 

 series along the Lamar River. Musopliyllum complication has never before 

 been reported outside of the Green River beds. Ficus ungeri and Tilia 

 populifolia are typical Green River plants, but are represented here by one 

 or two examples each. 



The species found in the Auriferous gravels are the only ones remaining 

 to be considered. Of the 1 1 species, Juglans rugosa, Quercus breweri, Salix 

 lavateri, and Quercus olafseni are open to doubt, as they are represented by 

 only one or two fragments each. Ficus asiminiafolia likewise depends upon 

 a single leaf, but it is a well-preserved one, and the determination is probably 

 correct. Aralia notata, another of the species, is very rare, if really found 

 at all, in the Auriferous gravels. The three remaining species are rela- 

 tively abundant, and there is little question as to the correctness of their 

 determination. 



The species whose distribution lies beyond the limits of the Park 

 having been passed in review, it will be of interest to note the obvious 

 affinities of certain of the more important new forms. Thus, Asplenium 

 remotidens is closely related to A. erosum, and Dryopteris iveedii and D. xantho- 



