CORRELATION. 



147 



to the Wilcox; in addition, SO per cent of its 

 species are found in the lloras of the liaton and 

 Denver formations of the Rocky Mountain 

 province. It may therefore be considered to 

 he essentially the same type of flora as that of 

 the Wilcox, one which, if it could be known in 

 its entirety, would be found to contain a num- 

 ber of identical species and othei-s ancestral to 

 those of the W^ileox. 



RELATION TO THE CLAIBOKNE FLORA. 



A large flora from difl'erent horizons in tlie 

 Claiborne fjroup has been more or less fully 

 descrilx'd in nnmuscript, but tiie only pubhshed 

 account is that of the smidl upper Claiborne 

 flora from Georgia descrilu'd by me in 1014 in 

 Professional Paper 84 of the I'nifed States 

 Geological Survey. Plants of lower Clail)orne 

 age have been collected by me in Arkansas, and 

 upper Claiborne plants are now represented in 

 the collections from Georgia, Alabama, Missis- 

 sippi, Arkansas, and Texas. 



The following Wilcox species have already 

 been I'ecognized in the Claiborne: Anditiia 

 eocenica, Taxodium duhium, Oriddaphne obiu- 

 sifolia, Sajnndvs inississippiensis, Sapindus 

 formostt^, Myrcia hentonensis, and Diospi/ros 

 bracJiysepala. Moreover there are Claiborne 

 species which are affiliated with W^ilco.x species 

 in the genera F'icus, Coccolobis, Pisonia, Engel- 

 hardtia, Cinnamomum, Persea, Nectandra, 

 Inga, Csesalpinitos, Sophora, Celastrus, Zizy- 

 phus, Ternstrcemites, Laguncularia, Combre- 

 tum, Terminalia, Conocarpus, and Mimusops. 

 Though only 2 per cent of the Wilcox species 

 have been recognized in the Claiborne, this figure 

 may be slightly increased wh(>n the Claiborne 

 floras are finally published. The community of 

 genera show that the Claiborne flora is similar 

 in its gener;d facies to that of the Wilcox, and 

 the very marked differences are in the main dif- 

 ferences in specific and not in generic types. 



COMPARISON OF WILCOX FLORA WITH OTHER 

 AMERICAN EOCENE FLORAS. 



PURPOSE OF THE COMPARISON. 



A comparison of the Wilcox flora with other 

 American Eocene floras adds but little to our 

 knowledge of the Wilcox. At the same time 

 it wLU shed .some light on the age of some of 

 these floras, as the Wilcox is very definitely 

 fixed stratigraphically and paleozoologically 

 and smce, as I will show subsequently, it can 



be very definitely convlated with the Euiopean 

 section. In my table of distrijjution and in 

 this discussion I Inive igncn'ed the Lance 

 formation of the Rocky Mountain and Great 

 Plains province, as the flora of that forma- 

 tion has never been fiiDy described, tliough it 

 is represented in the literatm-e by lists of 

 species that indicate a flora much less exten- 

 sive but essentially Fort Union in its facies. 

 Those who wish to make comparisons with 

 the flora of the Lance arc referred to thi> jnib- 

 lications of F. II. Knowlton on tliis sul)j<'ct. 



FLORA OF TIIE RATON FORMATION. 



WiUis T. Lee has proposed the name Raton 

 formation for a series of coal-bearing sand- 

 stones in the Raton Mesa country of north- 

 eastern New Mexico and southeastern Colo- 

 rado (the Raton and Trinidad coal fields), 

 which carry an abundant flora, recently de- 

 scribed in an unpublished paper by F. H. 

 Ivnowlton. The first plants from the Raton 

 formation to be studied were collected by Le 

 Conte in 1867 and submitted to Lesquereux, who 

 referred thom to the Eocene. Hayden visited 

 the region in 1869, and his collections were like- 

 wise studied by Lesquereux, who pointed out 

 their affinity with the ''Eolignitic" [WUcox] of 

 Mississippi, as it was know^l to him.' According 

 to Kjiowlton,- the Raton flora comprises 14Sspc- 

 cies, of which .5 occur in the-Laramie and about 

 40 in the Denver formation . From the floral rela- 

 tions, as well as the stratigraphic and structural 

 relations, Knowlton and Lee conclude that tlie 

 Raton formation represents the southward con- 

 tinuation of the Denver along the Rocky Moun- 

 tain front. The relation to the Wilcox, first 

 recognized by Lesquereux, is confirmed in the 

 recent studies, altliough the size and coastal 

 character of the Wilcox flora render the aflmity 

 less prominent than it was when comparatively 

 few species were known in each area. 



The followmg Wilcox species are represented 

 in the Raton flora: SahaUtfs grayanus, Jiujlans 

 berryi, Juylaiis schimperi, Eiu/dhardtia ettings- 

 liauseni, Dryophyllum moorii, Dryojiliyllum 

 tennesseensis, Fictts scMinpcri, Ficus monodon, 

 Finis Jiarrisiana, Ficus denveriana, Ficus pseu- 

 dopopulus, Ficus pseudolmediafoUa, Ficus 



> U. S. Geol. and Geog. Survey Terr. Fifth Ann. Kept., Suppl., p. 19, 

 1S72. 

 = Knowlton. F. H., Am. Jour. .Sci., 4lh ser., vol. 3.5, pp. 520-530, 1913. 



