222 The Upper Cketaceous Floras of the World 



Saliac deleta Lesquereux 

 Sapindus morrisoni Heer 

 Sterculia lugubris Lesquereux? 

 Tricalycites papyraceus Newberry 

 Viburnum robustum Lesquereux ? 

 Zizyphus lamarensis Berry 



Western North America 

 the western" united states 

 The Western Interior, so-called, embraces the vast area included in 

 the Great Plains and Boeky Mountain provinces. The plant-bearing 

 records extend from the base to the top of the Upper Cretaceous and are 

 scattered over an area extending from southern Kansas to the Arctic 

 Ocean. Much of this region, especially toward the north, is very insuffi- 

 ciently known. The records of fossil plants are based on the pioneer work 

 of Lesquereux, Newberry, and Dawson, that of the last being particu- 

 larly untrustworthy. In recent years Knowlton has made some admirable 

 contributions to the knowledge of the floras of the Montana group and 

 this author has also spent much time on a study of the floras of the 

 Laramie, but this latter work is, for the most part, unpublished. 



The Washita Series 

 The oldest plant-bearing beds of Upper Cretaceous age in this area are 

 those known as the Cheyenne sandstone of southwestern Kansas. These 

 form a part of the Washita division of the Comanche series of Hill, 1 and 

 are usually referred to the top of the Lower Cretaceous by American geolo- 

 gists, although foreign paleontologists long ago indicated their Ceno- 

 manian age. A large flora was collected from these beds by Ward and 

 Gould as long ago as 1897 and is now preserved in the U. S. National 

 Museum. This flora has never been studied and so cannot be enumer- 

 ated in the present connection, but both Knowlton and the writer have 

 examined it and are in agreement as to its age. This section was 

 described and the earlier literature was cited by Gould 2 in 1898. It 



1 Hill, R. T., 21st Ann. Rept. U. S. Geol. Survey, pt. vii, 1901, pp. 240-292. 



2 Gould, C. N., On a series of transition beds from the Comanche to the 

 Dakota in southwestern Kansas. Amer. Jour. Sci. (iv), vol. v, 1898, pp. 169- 

 175. 



