222 KNOWLTON 



Common to lower member and Arapahoe and Denver 22 



Common to lower member and Shoshone 35 



Common to lower r ember and other Eocene 15 



Common to lower member and Cretaceous [including Laramie and 



Montana.] 16 



Common to lower member and Tertiary [Eocene to Miocene] 68 



From the above table it appears that of the entire number of forms 

 now known in the lower member of the Fort Union only 16 species 

 are common to it and the Cretaceous, this including both Laramie 

 (11) and Montana (11), and of these there are 7 species which run 

 from the Cretaceous through the lower Fort Union into or above 

 the upper member of the Fort Union, thus leaving really only 9 

 species confined exclusively to the beds under consideration and 

 the Cretaceous below. Following is the list of the 16 species, the 

 asterisk indicating Montana species and the dagger Laramie species: 



^"fFicus trinervis. 



'fFlabellaria eocenica. 

 ^IfJuglans rugosa. 

 *^Myrica torreyi. 



* Magnolia tcnuinervis. 

 'fPalmocarpon palmarum. 

 fPlatanus haydenii. 



'^fPlataniis marginata. 



* Platanus platanoides. 

 f Platan us raynoldsii. 

 '\Quercus viburnifolia. 



^^Rhamnus salicifolius. 

 *fSabalites grayanus. 



* Salix angusta. 



* Trapa? microphylla. 



* Viburnum ■whymperi. 



A close analysis of the distribution of these species shows that, 

 for one reason or another, comparatively little weight is to be at- 

 tached to certain of them. Thus, Ficus trinervis, which occurs 

 only in the lower beds at Glendive, Montana, is a species of wide 

 distribution in the Montana and Laramie, and has been found in the 

 Shoshone. Flabellaria eocenica, reported from Converse and Weston 

 counties, finds its main distribution in the Laramie and occurs also 

 at Black Buttes. Juglans rugosa, of which there is but a single 

 specimen in the dinosaur beds at Yule, is of very wide distribution, 



