1899] MICROSCOPICAL JOURNAL. 49 



Diatoms Prove an Occidental Sea on the East of 

 the Rocky Mountains. 



By ARTHUR M. EDWARDS, M. D., F. L. S. • 



The Occidental Sea 1 have endeavored to describe, at 

 first in the American Journal of Science for 1891 and 

 elsewhere in various publications, and why I describe it 

 as Eocene, below the Miocene of California, I have also 

 stated. But the sea was only stated to be west of the 

 Rocky Mountains, between that range and the Sierra Ne- 

 vada. Some specimens I had from the east of the Rocky 

 Mountains seemed to be Eocene but I was not sure that 

 they were more ancient than the Iceberg period or Cham- 

 plain. In fact, I did not get any specimens that were 

 surely Eocene. Now, I have one that comes from the 

 "Public Lands" on the branches of the North Canadian 

 or Beaver Creek about thirty-five or forty miles from En- 

 glewood in the northeastern part of Kansas. This, Prof. 

 F. W. Cragin of the Colorado College calls the Loup 

 Fork terraine, and I have to thank him for an opportu- 

 nity of examining it. It is also east of the Rocky 

 Mountains and therefore extends, as I expected, the Oc- 

 cidental Sea to the eastward. I hope ere long to extend 

 it on the coast side of the Sierra Nevada and into Cali- 

 fornia. In fact, I have it from Shasta and Anacapa Is- 

 land on the coast, showing that it covered a vast extent 

 of country and was a large body of water. When a 

 sample was shown to Prof. Cragin, in 1888, the chalky 

 marl was thought to be of Cretaceous age and also car- 

 bonate of lime, in fact the same as chalk. But, he visited 

 the locality in 1890 and found that it was impossible, as 

 fossils in the same bed were land and lake animals. In 

 1896, he visited the locality again and confirmed the con- 

 clusion that the Loup Fork was lacustrine. He says that 

 "the great Loup Fork Lake which extended from middle 

 Kansas to the Rocky Mountains and from Texas to British 



