NO. 1873. 



CHARACTERS OF GIGANTOPTERIS— WHITE. 



511 



List of Plants from the Denver and Rio Grande Tunnel Beloic Swissvale, Colorado. 



CaUipteri.^, sp. 

 PsygmoplnjJluin cf. cuneifoUuni. 



Odontopteris subcrenulata Rost? 

 Macrostachya? sp. 



Sigillariostvobiis hastatus. 

 Walchia cf. piniformis. 



Walchia cf. imbricata. 

 Rhabdocarpos dyadicus Geinitz? 



From beds apparently about 1,550 feet higher between Badger 

 Creek and the Wells ville "One mile" signal beds were located con- 

 taining SchizoiHeris, Callipteris, Odontopteris, Walcliia, and RJiaMo- 

 carpos. It is therefore probable that 2,000 feet, at least, of this 

 section of the "red beds" is Permian. 



Fragmentary and incompletely representative of the several 

 floras as the lists may be, they yet show some interesting aspects of 

 the distribution of the Permian species. Thus, the genus WalcJiia, 

 unknown in the Permian of the Appalachian trough, is present at 

 most of the localities, while Callipteris, which is very meagerly 

 represented in eastern North America, is common and higlily differ- 

 entiated in Kansas and Colorado. Gompliostrohus, another type 

 characteristic of the Permian of western Europe and hitherto unlaiown 

 in North America, is present in Kansas, Colorado, Oldahoma, and 

 Texas. The common type of simple leafed Tseniopteris, diagnostic 

 of the western European lower Permian, is nearly ever^^where present, 

 sometimes accompanied by other forms, one of which, with distant, 

 simple nerves, is of distinctly ]\Iesozoic aspect. 



In addition to the many Callipteris and Walchia species just men- 

 tioned, the provisional lists from the western Permian include a 

 number of other forms near to, if not identical with, diagnostic Old 

 World Permian types hitherto unknown in tliis continent. Among 

 these are Scliizopteris cf. tricliomanoides, Sphenopteris lehachensis, 

 Pecopteris geinitzi, Pecopteris pinnatifida, Cladopldebis'i cf. tenuis, 

 Scolecopteris elegans, Odontopteris subcrenulata, Txniopteris ahnor- 

 mis, Annularia spicata, Rhabdocarpos cf. dyadicus. 



It is probable that several cosmopolitan species of Pecopteris and 

 Sphenopteris will be found to have accompanied Txniopteris multi- 

 nervis from western Europe to eastern Cliina. 



The examination of the materials from the Western Interior and 

 Rock}'' ]\Iountain basins shows that wliile the flora is composed 

 mainly of t3q:)es common to western Europe which have undoubtedly 

 been distributed along essentially the same northeastern Arctic- 

 American route by which the Pennsylvanian floras migrated, it con- 

 tains also a somewhat unique element unmistakably derived from 

 eastern Asia. The latter includes the Gigantopteris, the pecuhar 

 Annularia, and a Txniopteris form, to wliich should possibly be 

 added the representatives of Araucarites and Neuropteridium. The 



