Fossil. FLORA. 665 



Rocks and Black Buttes, WyomiiiL;-. The most interesting species is Trapaf 

 microphyJlu. It is represented by several perfectly characteristic specimens. 

 This species was tirst described from Point of Rocks, AVyoming, and was 

 found later by Professor Ward in lowest Fort Union beds, near the month 

 of the Yellowstone River. The Wolverine Creek specimens approach 

 closest to Professor Ward's specimens. Professor Ward is of the opinion 

 that these lower beds represent the Laramie, since the plants in them differ 

 from those in the nndonbted Fort Union beds. 



The tln-ee species from the divide between Snake River and the 

 sonthern part of Yellowstone Lake are of little value in determining the 

 age. Geonomites scliimppri has never been fonnd in any other locality, and 

 D'wspiiros stenosepala is verv doulitful indeed. It has not since been col- 

 lected, and the specimen on which Lesquereux based his determination can 

 not now be fouml. The only remaining species, Anemia suhcretacca or 

 Gyiuiiognunnta haijdcuii of Lesquereux, has a wide distribution, having been 

 found in the Laramie, Denver, and Eocene. 



DESCRIPTION OF FOSSIL PLANTS FROM THE TERTIARY OF THE 

 YELLOWSTONE NATIONAL PARK. 



PLANTS, EXCLUSIVE OF FOSSIL WOOD. 



FILICES. 



WOODWARDIA PREAREOLATA U. Sp. 

 PI. LXXIX, fig. 1. 



Frond pinnate; pinnre alternate, lanceolate, with slightly undulate 

 margins, connate at their bases, forming a broad wing on the rachis; nerva- 

 tion strongly reticulated, consisting of one or two rows of long lacuna? 

 next to the main rachis and along the secondary rachis, and the remainder 

 forming large polygonal, slightly elongated, meshes. 



Unfortunately the specimen figured represents the only example found. 

 It is far from perfect, being only a segment from the middle of a frond, 

 and consequently no idea can be gained of the outline of the whole frond. 

 The segment of the main rachis is 8 cm. long. The pinnae are regularly 



