AGE OF THE AKAI'AHOE AND DENVER. 223 



by various members of the Hayden survey. Although it is expressly 

 stated by the <re< doyists in their reports, and by Lesquereux in his mono- 

 graphs, thai several widely separated plant horizons existed, as, for example, 

 the vertical coal beds and the horizontal strata of Table Mountain, the 

 published descriptions in many cases do Qoi specify locality further than 

 as "Golden, Colo." Nor do the original labels or catalogues contain more. 



Thus at the time the Denver beds were first described the published 

 fossil flora of Golden consisted of over 100 species. In his monograph 

 "Cretaceous and Tertiary Floras" (1883) Lesquereux specifies the coal 

 measures of the Laramie as the "habitat" of but 3 species and only l.'i are 

 referred to Table Mountain. By searching the original descriptions and 

 noting incidental references in the various reports it may be ascertained 

 that 1) species came from the coal measures and 16 from Table Mountain. 

 Of the remaining 75 per cent of the Golden flora, as known in L888, the 

 writer has been unable to find published or otherwise recorded evidence of 

 the horizons from which they were obtained. 



In 1888 Lesquereux added 68 species to the flora of Golden, without 

 specifying the horizon of a single one of them. In 1886 Prof. L. F. Ward 

 published his synopsis of the Laramie Flora and in his table of distribution 

 included all the species of Lesquereux from Grolden, most of which were 

 from unknown horizons. At various times in the course of the investigation 

 of the Denver beds, fossil plants were sent to Profs. L. F. Ward and J. S. 

 Newberry, with the request that it' possible they should discriminate 

 between Denver and Laramie floras. In every case the reply was that no 

 difference could be seen. The evident explanation of this inability to 

 distinguish the two floras was that what was by them considered the 

 "Laramie flora" embraced also all known Denver plants, and the data 

 did not exist in the published record by which the species from the two 

 formations could be separated for comparison. 



From examination of the published data concerning the Middle Park, 

 Bozeman, and other local floras, especially those of Wyoming localities, it 

 appears that an entire revision of the earlier publications is necessary 

 before a correct list of Laramie plants can be compared with that of post- 

 Laramie species. 



