CORKELATIOX. 



145 



Temstroemites lanceolatus. 

 MjTcia bentonensis. 

 MjTcia grenadensis. 

 Eugenia densinen-ia. 

 Eugenia grenadensis. 

 Temiinalia wilcoxiana. 

 Melastomites amerieanus. 

 Aralia acerifolia. 

 Aralia notata. 

 Aralia jorgenseni (?). 

 Comus sluderi. 

 Chnsophyllum ficiiolia. 

 Bumelia grenadena^. 

 Biunelia americana. 

 ilimusops missksippiensis. 

 DiospjTos brach>-sepala. 

 Fraxinus johnstrupi ("?). 

 ApocjTiophyllum sapindifoliuni. 

 ApocjTiophyllum mi^d^ppiensis. 

 ApocjTiophylluni constrictum. 

 Citharexylon eoligniticum. 

 Exostema pseudocaribieuni. 

 Calycites osm-aiormi^. 

 Carpolithus grenadensis. 

 Carpolithus sophorites. 

 Carpolithus pUocarpoides. 



Of these 112 species, 56, or exactly half, are 

 peculiar to the Grenada formation; the other 

 half range upward from the older Holly Springs 

 and Ackerman formations. The locahties of 

 Grenada age include none from Mississippi, ex- 

 cept Grenada in Grenada County. In Tennessee 

 the deposits at Somerville in Fayette County 

 and near Trenton in Gibson County are of this 

 age. In Kentucky the deposits at Boaz in 

 Graves Coimty and at Wickliffe in Ballard 

 County are of Grenada age. In Arkansas the 

 deposits at Benton and vicinity m Saline Count}" 

 and at MiUvern in Hot Springs Comity are be- 

 Ueved to be of Grenada age. In Louisiana the 

 beds at Coushatta in Red River Parish, which 

 contain a large flora, and at Mansfield and 

 around Nabortpn in De Soto Parish are of this 

 age. In Texas the beds at Old Port Caddo Land- 

 ing in Harrison County belong here or at the top 

 of the Holly Springs horizon; the beds exposed 

 in the bluff on Sabine River, near Hamilton in 

 Sabine County, the beds on Colorado River in 

 Bastrop County, and on Calaveras Creek in 

 Wilson County, are believed to be of this age. 

 Figure 10 shows the approximate stratigraphic 

 relations of these outcrops. 



RELATION TO CRETACEOITS FLORAS. 



The relation of the Midway and Wilcox floras 

 to those of the Lower Cretaceous of Texas or 

 of the Potomac group of the Middle Atlantic 



50243"— IG^— 10 



slope is so remote that direct comparisons are 

 impossible. The Lower Cretaceous flora be- 

 came practically extinct before the close of the 

 L'pper Cretaceous, and the abimdant ferns, 

 cycadoph^-tes, and to a less extent the conifers 

 were replaced by the premmtial representa- 

 tives of the now dominant race of plants, the 

 Dicotyledons. At the close of the Upper Cre- 

 taceous or the dawn of the Eocene a second 

 modernization of the floras of the world prac- 

 tically wiped out all the older t}-pes. 



Very extensive Upper Cretaceous floras are 

 now known from both Xorth .Vmerica and 

 Europe, as well as from the .Vrctic regions. 

 North America is especially rich in Upper Cre- 

 taceous plants, several himdred species having 

 been described from the Dakota sandstone and 

 from later Cretaceous deposits of the interior 

 region. The Coastal Plain from New York to 

 Texas is rich in Upper Cretaceous plants, and a 

 large flora has been described by me from beds 

 of tliis age in the emba\-nient area in Alabama, 

 Mississippi, Tennessee, and Texas. This Up- 

 per Cretaceous embayment flora includes about 

 1.50 species, most of which come from the Tus- 

 caloosa formation of western Alabama. 



More than 40 per cent of the genera are not 

 represented in the existing flora. The most 

 abundant orders are the Ranales, Coniferales, 

 and Urticales. The largest genus is Celastro- 

 phyUum. Of the 123 species of Dicotyledonte 

 S7 per cent are Choripetahv and only 13 per 

 cent Gamopetala?. The flora as a whole indi- 

 cates less tropical conditions than the early 

 Eocene floras of the emba^-ment area. 



Not one of these Upper Cretaceous species 

 passes over into the Eocene; in fact, none of 

 the Wilcox species occm- m the Cretaceous of 

 this or any other known area.' The follo^ving 

 genera recorded in the Upper Ci-etaceous of 

 the embajnnent area are not foimd in the Mid- 

 way ( ?) or Wilcox : 



.\bietites. 



.\cerates. 



-Vndromeda. 



.Vndrovettia. 



.\raucaria. 



Bauhinia. 



Brach>"phyllum. 



Celastrophylhiiu. 



Cephalotaxospermum . 



Gissites. 



Cladophlebis. 



Cocculus. 



Colutea. 



Comophyllum. 



Cuuningliamite- . 



Cj'oailinocarpiis. 



Dammara. 



Dermatophyllites. 



' \ possible exception to this stfitcment is Artocarpus lessiffianOf 

 which has been recorded from the Larumic, but which I am uot sure 

 came from that horizon. 



