37 



sented in the Mascall by leaflets which closely resemble 

 an midoscribed Florissant species which may be a Ber- 

 beris, but is certainly not an .Esculus. 



ton to d. (iciinfa (Inger) I leer, which occurs in Europe 

 at (Eningen. 4 



Three other genera, Phragmites, Cyperacites and 

 Sniilax, are non-arborescent, and have no particular sig- 

 nificance. 



Thus it would appear that in the Middle Miocene 

 period Ginkgo and (Jlyptostrobus- if we may accept the 

 determinations— had not yet retreated frosn the Amer- 

 ican continent, but survived at least in the northwest. 

 For the rest, the Mascall flora is no doubt a lowland one 

 as compared with that of Florissant, and this alone would 



pect to find Taxodium growing around a mountain lake. 



Dr. Knowlton has described (Monog. TJ. S. Geol. Sur- 

 vey. Vol. IV2. part 2 ) an extensive flora from the Fellow- 

 stone, which he regards as Miocene. The fossil plants 

 of the Yellowstone National Park are divided by him into 

 three series: (1) Fort Union, which is Basal Eocene, 

 (2) Intermediate, said to be Miocene, and (3) Lamar 



cerned, but the others must he compared with the flora 

 of Florissant. Considering the relative proximity of the 

 Yellowstone beds to those of Colorado, one would expect 

 to find much similarity and even identity in the plants: 

 hut this is not the case. The difference of locality, with 

 a moderate difference in time, might perhaps account for 

 the diversity of species; but the Yellowstone flora as a 

 whole does not impress one as being so modern as that 

 of the Mascall beds or Florissant, while there is a sig- 



I have extracted from Knowlton 's tables a list of all 

 the Yellowstone "Miocene" plants said to occur else- 

 where or in the Eocene, with the following result : 



