W. Cross — Denver Tertiary Formation. 273 



strata. The writer cannot find any statements from which, the 

 horizons of the remaining 75 per cent of the Golden fossil 

 plants can safely be assumed. Forty new species found only 

 at Golden are not assigned to definite horizons. 



The original specimens described by Lesquereux have been 

 sent to the U. S. .National Museum, where, through the cour- 

 tesy of Prof. Lester F. Ward, Curator-in- charge of fossil plants, 

 they have been examined by the writer within the past year. 

 The following statements are made with Prof. Ward's permis- 

 sion : 



Only 79 species of the Lesquereux collection from Golden 

 could be found, the remainder being temporarily lost sight of 

 in the confusion naturally attending the rapid growth of the 

 Museum in such limited space. The specimens bear numbers, 

 but there are very few labels giving localities, and the Museum 

 catalogue contains no details, the locality " Golden, Colorado," 

 standing for all alike. 



Under the circumstances the lithological characteristics of the 

 matrix containing the fossils is the only available means of de- 

 termining the horizons from which they were obtained. The 

 peculiar yellowish brown sandstones of Table Mountain are 

 clearly distinguishable from the quartzose sandstone of the coal 

 horizon, to anyone acquainted with the rocks, and the follow- 

 ing result of an examination as to the matrix is satisfactory to 

 the writer, though it may not be equally so to others. 



Of 79 species found, 18 occur in what is judged to be Lara- 

 mie sandstone or shale, and 59 in distinct Denver beds of Table 

 Mountain, while 7 occur in both rocks, and 9 cases are in doubt. 

 Lesquereux gives horizons for 6 species which were not found. 

 By combining the two sources of information we get probable 

 indications of horizon for 76 per cent of the Golden fossil 

 plants ; 22 per cent came from true Laramie strata and 63 per 

 cent from Table Mountain beds ; 9 per cent occurring in both 

 formations.* 



* After this article was completed the writer received a pamphlet by Prof. Les- 

 quereux entitled: — "Fossil plants collected at Golden, Colorado." (Bulletin 3, 

 vol. xvi, Museum of Comparative Zoology at Harvard College, Dec, 1888.) This 

 paper (written in 1884) describes the Golden plants in the Museum at Cambridge, 

 Mass. "They represent 118 species, or vegetable forms considered as species, 28 

 of which are admitted as new species, .... and 32 as new for the Flora of the 

 Laramie Group, but known from other localities, making therefore for that Flora 

 an addition of 60 species." There is in this paper no mention of a definite hori- 

 zon or of an exact locality for a single species beyond the statement that they 

 were collected at Golden and came from the Laramie. Prof. Arthur Lakes of 

 Golden, who collected these specimens, has informed the present writer, upon 

 inquiry, that he thinks the plants were all obtained from Table Mountain or Green 

 Mountain, and that "none of them came from the proximity of the lower Coal 

 Measures." If this is true all of these sixty species belong to the Flora of the 

 Denver Formation, and not to the Laramie, as far as known. It is probable that 

 more than sixty of the species from Golden, described by Lesquereux in the 

 " Tertiary Flora" are likewise unknown, aa yet, in true Laramie strata. 



